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#19 ttonon

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Posted 13 March 2011 - 09:47 AM

Hi Ardie,

Let me also summarize what I see as the difference between our views on the issue. We both agree that, with “windsavers” - valves placed on the back side of the slot of each reed -, single-reed bends are greatly facilitated, for all of the ten holes in a standard “blues harp” instrument. For me, this fact may, but not necessarily, indicate that single-reed bends are possible in the un-valved instrument, and I’m surprised that others – call them “the Johnston crowd” - claim that the only “normal” bends made with the unvalved instrument are “double-reed bends” – bends that require the presence of two reeds in the same slot, accompanied by the influence of an air resonator (oral/vocal tract). I myself do not claim that these people are wrong, and I’m willing to accept the possibility that they are right. (Johnston’s paper gives strong experimental and theoretical evidence that they are right.)

If I understand your position, you seem to differ from me only that you say that these people are indeed wrong. You simple go further than I do, on this issue.

I must thank you for your document, which is valuable here, and it helps make certain things clear to me. For one, it lays out before us all what the Johnston crowd claim; i.e. that the only “normal” bends you can do on an unvalved blues harp are bends on reeds that have, as accompanying reed, one with lower pitch. Look at your evidence on this point. The only exceptions you show are with holes 5 and 6 on the blow, where the accompanying reed is of higher pitch. You indicate that the bent sound is difficult to hold, because of the parentheses. Thus, would you not agree that your chart gives considerable evidence for their claim?

5) As long as I haven't got such evidence I remain sceptic that there IS any involvment by the "secondary reed" at all and I wonder if there might be some fundamental misunderstanding messing things up

Okay, I say we are both skeptical, but maybe we just haven’t yet heard enough of the evidence that’s already out there. I read Johnston’s paper many years ago, and I honestly cannot remember how convincing it is. I need to read it again before making any more statement on it.

Concerning the evidence you seek, I’ll mention again that the Asian free reed is indeed a reed that necessarily operates as an “opening” reed. If you don’t understand what this term means, I suggest you read Cottingham’s paper, referenced above. As the Johnston crowd explains, the additional reed in the harmonica operates as an opening reed during the bend, in the same way as the Asian reed, and both require coupling to an air resonator. But perhaps the best evidence I can point to at the moment is the Johnston paper. If you (or anyone else) would like me to send you a copy, email me with your address. In the Johnston paper, both experimental and theoretical evidence is presented. With the experiments, they made use of an actual unvalved instrument, powering it through a resonator of variable geometry. I should read the paper again. Being only an amateur, I’m not as familiar with the literature as I could/should be.

6) As far as I can understand bending primarily involves a changed influence from the air stream and pressure on the singular reed.
The vocal tract - when acting as a resonator in these cases - only adds tonally to the sound produced by the "primary reed". The assumed involvement by the "secondary reed" I still this far regard as a theoretical construction without practical evidence. There is a considerable tonal difference between bending simply by using overblow or overdraw technique with very tight lips ( as if you just whistle into the harmonica) or a technique opening up the mouth ( "swallowing the tongue method") but I don't yet understand or accept that the later means any involvement (="coupling") of the "secondary" reed.If one looks at the theoretical combination patterns between the "primary" and "secondary" reeds in the same chamber there is no sensible pattern in the note results.How are for example the options explained to do continuous pitch transitions from D-C#-C or B-Bb-A-Ab while the "secondary reed" is completely inactivated??

Here, I think you go too far, and I think there are physical errors in your understanding. I believe you are in error when you say, “bending primarily involves a changed influence from the airstream and pressure on the singular reed,” if, by “bending” you mean the normal bending – not overblow. With overblow, I agree, a non-uniform air flow (i.e. jets) may be involved. But not so with the normal bend, on the draw. It’s not impossible to form a non-uniform airflow through the reed when you draw. The flow through the reed is then upstream of your mouth, where the vacuum is, causing an air flow approach to the reed is that must be uniform. I’m not sure what happens when you do a normal bend on an unvalved harp with a blow – one reason being because I never learned how to do it. But with a valved harp, the blow bend is produced also by a uniform flow, without the “whistling” you explain for overblows.

If one looks at the theoretical combination patterns between the "primary" and "secondary" reeds in the same chamber there is no sensible pattern in the note results.

I strongly disagree. As I noted above, the patterns I see between the primary and secondary reeds give strong evidence for the Johston crowd. One last point I can make is by asking, since you are aware of overblowing (whistling) techniques, isn’t it true that, when you overblow, you also force the reed to speak with an airflow that is in opposite direction to the ordinary? I’m not 100% sure, but I’m pretty sure that, with overblow, the main speaking reed is again operating as an opening reed.

How are for example the options explained to do continuous pitch transitions from D-C#-C or B-Bb-A-Ab while the "secondary reed" is completely inactivated??

I didn’t know that such large bend excursions were possible with the unvalved harp. If it’s true, then I don’t know the answer to your question.

I think at this point, we really need someone with more knowledge to chime in.

Best regards,
Tom

#20 Ransom

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Posted 13 March 2011 - 02:45 PM

You fellows seem to be having trouble reproducing my results, so I have recorded them to share with you.



The video proceeds as follows: I play a draw, then a blow, then a draw, then a blow. Observe that the blow reed is activated during the blows, and not activated during the draws. Then I play two draw bends. Observe that the blow reed activates, with amplitude increasing as the bend deepens. Then I seal the blow reed with a finger, and play three bends: the first one stopping at the bottom, the other two going down and coming back up. Observe that the note chokes on each of the sealed bends.

#21 ttonon

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Posted 13 March 2011 - 09:04 PM

Hi Ransom,
Thanks for going through the trouble to make the video. I’m always amazed by the power of the web. Let’s all hope we can keep net neutrality.

You fellows seem to be having trouble reproducing my results, so I have recorded them to share with you.

No, no, no, it's easy to reproduce your results. Let me explain.

The fact that the reed chokes when you try to draw bend while covering the slot proves to me that you have very good acoustic coupling between the reed and your vocal cavity. The coupling in this case is much stronger than when the slot is not covered. Thus, in order to produce the bend with the covered slot, you cannot use the same vocal tract geometry that you use with the uncovered case. I suggest you try practicing the covered bend, but with only a slight modification of your vocal cavity. It’s easy to choke a reed when you have good acoustic coupling. I can do the same thing as you, with little effort.

This effect is also easily shown when you try to play accordion reed blocks as you would play harmonicas. The reed leathers present likewise allow strong coupling, and you cannot be very aggressive with your throat gymnastics.

In a thread on this forum a couple weeks ago, there was a discussion on why drilling a hole somewhere in the reed cavity would prevent some very high concertina reeds from choking. All these phenomena are similar: when the air coupling between a reed and an associated geometry is strong enough, and when the resonant frequency of the air geometry is close enough to that of the reed, the reed will choke.

So in a sense, the fact that you can now choke the reed with your vocal tract proves how immensely improved acoustic coupling to your vocal tract becomes. You just have to be a little less aggressive with your oral talents.

The fact that the uncovered bend is easier for you only suggests to me that this is the situation you are most used to. Bear in mind that both Ardie and I find it a trivial task to bend on a draw with covered blow slots. The fact that you can’t do it doesn’t prove we cannot. I suggest only that you need a little more practice. This is not surprising to those who are aware of the intricacies in playing a musical instrument.

The fact that the blow reed vibrates in the uncovered case may lend support to the Johnston crowd on their claim that a blow reed of lower pitch is required for the normal bend. But at the same time, it doesn’t prove their claim, simply because we don’t really know where the sound is coming from. It would be interesting if, during this bend, you were able to cover the blow slot, without the slightest change in any other parameter of the bend (vocal tract shape and airflow intensity) I’ve tried this many times, and it isn’t easy to do the experiment controlled, when I use a spare finger to cover the slot. My conclusion is, again, the blow reed isn’t really participating in the bend. It’s not surprising to me that it will vibrate during the bend, but only in the manner of a passive sympathetic action. Remember now, the vocal tract in this case may have a resonance frequency closer to the BLOW reed, in which case the air vibration is what’s causing the blow reed to sympathetically vibrate, not the other way around.

One last point: it seems to me that normal draw bends are relatively easy on the lower half of the unvalved harp perhaps because the resonant frequency of the modified vocal tract becomes close to that of the blow reed during the bend. This coincidence of frequency causes the blow reed to sympathetically vibrate, which, in effect, partially seals the blow slot, increasing acoustic coupling between the slot and the air column. On the other hand, with the upper half of the instrument (where the secondary reed has pitch higher than the primary reed) the resonant frequencies of the vocal tract and the blow reed are now too far apart to induce sympathetic vibration in the blow reed. Thus, sufficient acoustic coupling with the air column is not achieved, and bends are much more difficult because of air leakage through the blow slot. The same comments apply of course to blow bends. These statements are only guesses and would require verification by experiment, and possible theoretical study.

I really wish someone more knowledgeable than me on harmonica playing would chime in here. I’m just winging it here.

Best regards,
Tom

Edited by ttonon, 13 March 2011 - 09:06 PM.


#22 Ransom

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Posted 13 March 2011 - 10:38 PM

Hi Ransom,
Thanks for going through the trouble to make the video. I’m always amazed by the power of the web. Let’s all hope we can keep net neutrality.

I myself took a moment to marvel how amazing it is that we have an internet where we can do stuff like that. I favor the condition of net neutrality, but am not sure that I favor legislation "supporting" it.

No, no, no, it's easy to reproduce your results. Let me explain.

Oh, good! Here I was worried that you two were off reaching some kind of consensus without me. Looks like I needn't have worried particularly.

The fact that the reed chokes when you try to draw bend while covering the slot proves to me that you have very good acoustic coupling between the reed and your vocal cavity.

Why, thank you! I'm also told I have good cranial movement, though that didn't take as much practice. =)

The fact that the uncovered bend is easier for you only suggests to me that this is the situation you are most used to. Bear in mind that both Ardie and I find it a trivial task to bend on a draw with covered blow slots. The fact that you can’t do it doesn’t prove we cannot. I suggest only that you need a little more practice. This is not surprising to those who are aware of the intricacies in playing a musical instrument.

Since you have taken my experience into account, I am prepared to (provisionally) accept what you say at face value. I don't know that I care to practice enough to accomplish the feat myself at this point.

One last point: it seems to me that normal draw bends are relatively easy on the lower half of the unvalved harp perhaps because the resonant frequency of the modified vocal tract becomes close to that of the blow reed during the bend. This coincidence of frequency causes the blow reed to sympathetically vibrate, which, in effect, partially seals the blow slot, increasing acoustic coupling between the slot and the air column. On the other hand, with the upper half of the instrument (where the secondary reed has pitch higher than the primary reed) the resonant frequencies of the vocal tract and the blow reed are now too far apart to induce sympathetic vibration in the blow reed. Thus, sufficient acoustic coupling with the air column is not achieved, and bends are much more difficult because of air leakage through the blow slot. The same comments apply of course to blow bends. These statements are only guesses and would require verification by experiment, and possible theoretical study.

Hmm! This hypothesis is interesting and novel to me. Thank you for propounding it.

I really wish someone more knowledgeable than me on harmonica playing would chime in here. I’m just winging it here.

Probably not the greatest place for it, eh? I'm not a regular at any place for harmonica physics, but I think I know a couple of places you could ask at.

#23 Ardie

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Posted 14 March 2011 - 02:01 AM

I make a fairly short comment this time..

Ransom, I see what you mean but my conclusions are different...
Tom, and so far they are somewhat different from Yours as well..

1) I don't accept the "Johnston crowd" description regarding the necessity of engagement by the "secondary" reed.Furthermore I can't yet find any sign of its importance for producing the bend itself - but the presence of the reed - open or valved - influences the ease/efficiency of the bending. The vocal tract I regard as an additional device to flavour the already bent sound.

2) Regarding my problems accepting the possible sound effect from a "western free reed" vibrating by a wrongly directed air flow I thank you in advance for your generosity Tom and will send a private message to you with my email address if you kindly might send some copies of the mentioned papers later !

3) My present position is this: Since I can do the necessary bends while blocking the "secondary" reed and on top of that valving or blocking the secondary reed facilitates the bending procedure my primary thought can only be that the bending phenomenon itself ( with the harmonica)is related to the physics of the primary reed only.The bending seems to be possible to achieve gradually lowering the pitch ( say from B-Bb-A-Ab)of that same reed and my impression is that this is achieved by forcing the reed to give a lower pitch.Can the capacity for this pitch lowering be related firstly to characteristics of the reed itself? Frame thickness? Springiness of the metal?

4)Tom, I do not of course reject the known presence of resonance coupling in sound production of the Sheng for instance and I am very curious about your own invention which might shed a great deal of light on the subject.
Bending the concertina notes ( which as said *can* be done) seems to be similar to harmonica bending but there is no "vocal tract" or similar involved there !?

#24 Ardie

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Posted 15 March 2011 - 08:36 AM

3) My present position is this: Since I can do the necessary bends while blocking the "secondary" reed and on top of that valving or blocking the secondary reed facilitates the bending procedure my primary thought can only be that the bending phenomenon itself ( with the harmonica)is related to the physics of the primary reed only.


To illustrate the above a little more I made this simple experiment today:
I used a vacuum cleaner to effectuate the draw - by just holding the end of a 8mm/4mm rubber tube (connected to the cleaner) against the harmonica holes - and it was possible ( though a bit tricky) to produce the common draw bends on holes 1-6 with the normal instrument and likewise with all the blow reeds blocked ( thus safely inactivating the "secondary reeds").

This method as far as I understand likely eliminates a significant importance from a resonator like the vocal tract. What I had to do to bring about the bend was to alter the angle between the tube and the hole and manipulate the distal 10mm of the rubber tube - something I mean resembles the "kissing" connection between lips and instrument I use when doing the bends myself without any feeling that the inner mouth and tongue are engaged.
This type of draw bend is "thinner" and not as powerful and "sonorous" as when the mouth is opened up but my point is that it is obviously practicable and indicates that the theoretical involvement of the "secondary reed" might be just that : an unnecessary theoretical construction.
An intriguing factor still is the bending note distribution between holes 1-6 and 7-10...

Add: An important WARNING: If trying to imitate the experiment, take care that the vacuum cleaner is not overheated and burns !

#25 Ransom

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Posted 15 March 2011 - 10:28 PM

Speaking of bent notes! Is it just me, or does Rainer Süßmilch throw a couple of bends into "Bare Svetos" on English International?

#26 Ardie

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Posted 15 March 2011 - 11:17 PM

Speaking of bent notes! Is it just me, or does Rainer Süßmilch throw a couple of bends into "Bare Svetos" on English International?


Certainly sounds so. That is about as much bending I barely can manage too with the English but one I have heard who's really got the knack of it is Anglo player Bertram Levy.

#27 JimLucas

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Posted 16 March 2011 - 01:15 AM

Speaking of bent notes! Is it just me, or does Rainer Süßmilch throw a couple of bends into "Bare Svetos" on English International?

Not just you.



#28 Ardie

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Posted 16 March 2011 - 11:46 PM

The fact that the blow reed vibrates in the uncovered case may lend support to the Johnston crowd on their claim that a blow reed of lower pitch is required for the normal bend. But at the same time, it doesn’t prove their claim, simply because we don’t really know where the sound is coming from. It would be interesting if, during this bend, you were able to cover the blow slot, without the slightest change in any other parameter of the bend (vocal tract shape and airflow intensity)...


Tom, I've tried to test this..see post #24.. :

To illustrate the above a little more I made this simple experiment today:
I used a vacuum cleaner to effectuate the draw - by just holding the end of a 8mm/4mm rubber tube (connected to the cleaner) against the harmonica holes - and it was possible ( though a bit tricky) to produce the common draw bends on holes 1-6 with the normal instrument and likewise with all the blow reeds blocked ( thus safely inactivating the "secondary reeds").

This method as far as I understand likely eliminates a significant importance from a resonator like the vocal tract.


What do you say? I regret I didn't manage to make the test complete all over the harp and I was worried about the vaccum cleaner. Have to make some other arrangement to continue.

.. My conclusion is, again, the blow reed isn’t really participating in the bend. It’s not surprising to me that it will vibrate during the bend, but only in the manner of a passive sympathetic action. Remember now, the vocal tract in this case may have a resonance frequency closer to the BLOW reed, in which case the air vibration is what’s causing the blow reed to sympathetically vibrate, not the other way around.


OK...but we both found it *easier* to do the bends with blocked or valved "secondary reeds", this intrigues me a lot. What about You? I am reading the Johnston paper and have to do it more...

One last point: it seems to me that normal draw bends are relatively easy on the lower half of the unvalved harp perhaps because the resonant frequency of the modified vocal tract becomes close to that of the blow reed during the bend. This coincidence of frequency causes the blow reed to sympathetically vibrate, which, in effect, partially seals the blow slot, increasing acoustic coupling between the slot and the air column. On the other hand, with the upper half of the instrument (where the secondary reed has pitch higher than the primary reed) the resonant frequencies of the vocal tract and the blow reed are now too far apart to induce sympathetic vibration in the blow reed. Thus, sufficient acoustic coupling with the air column is not achieved, and bends are much more difficult because of air leakage through the blow slot. The same comments apply of course to blow bends. These statements are only guesses and would require verification by experiment, and possible theoretical study.


When I try to assimilate this hypothesis I meet a problem to understand what the factual *physical* correlate may be concerning the bent results - the pitch transition for instance from B-Bb-A-Ab. *How* can we explain the resulting frequences as an interference between the primary reed, the secondary reed and the vocal tract? This also has to be objectified in a recording of the sound spectrum. OR - can it possibly/partly be a non-physical phenomenon - i e perceptual phenomenon which comes up in the inner ear and nervous system like "combination tones" ?

I'm not a regular at any place for harmonica physics, but I think I know a couple of places you could ask at.


Please find out and report. Although this maybe has become more harmonica related than concertina related general free reed physics might be of some interest for any squeezebox player.

#29 Johann

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Posted 17 March 2011 - 05:57 AM

Hi all,

I konw i am not asked but, may be my experience with tuning reed will shad some light on it.

First my be the truth is somewhere in between, and the second reed is of minor interest in this Story.

Still now my experiences:

As in the process of tuning reeds, i would like if no coupling between reeds, sounded at the same time would take place.

1. Cooling takes place without changing air column at all, because the reeds are reed from accordions mounted on the tunning table or sounded in the instrument. I use Dirk Accordion Tuner in most cases, this tuner shows two or more reeds at the same time.

The tunning problem comes up in the case off tuning tremolos of two or more reed at nearly the same pitch.
With wet tremolo the problem is not relay a question.

Tuning the second reed will always effect the pitch of the first reed to some extent, so in many cases the first reed has to be returned as well, if the pitch divination is more as tolerable.

2. The same Problem arises with reed being a Octave apart
The Fundamental bass reeds on Helicon Instruments are rather difficult to tune, because the copping effect for the helicon reeds (fundamental + oktav) sounded in the same camber is relay strong. Bass reeds not tuned well will result in problems if the are forced to sound with more power. With low volume the my be unosonic on more volume the start to sound on different pitch, resulting in a ugly woowoow... effect.

3. Tuning accompanied reed for chords with reeds on just 3rds and 5th is also difficult. If tempered chords are used the problem is not rely present.

4. In all this cases the cooling effect is clearly present and can be seen on the tuner, or heard in the work process going on.

5. In this cases i don't see a noticeable pitch change if the reeds are more as a quarter note apart.

6. The reeds dont need to be on the same pitch, the effect takes place on harmonics as well.

I hope this experience, is of interest.

Best regards, Johann

#30 ttonon

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Posted 17 March 2011 - 11:11 AM

I really wish someone more knowledgeable than me on harmonica playing would chime in here. I’m just winging it here.

Pat Missin is a notable authority and a very accomplished musician when it comes to harmonicas. He maintains an exhaustive informational web site on harmonicas and other free reed instruments: http://www.patmissin.com. I invited Pat to make relevant comments in this thread, and he came back with the following response. Some of the ideas he expresses have already been mentioned, and I've explained my own views, some of which don't completely accept the normal bending explanation that Pat gives.

There's also a relatively new development for free reed instruments, and Pat points this out at the end, linking us to a very interesting sound file he himself recorded. I do believe this latest development can have a significant effect on the future development of concertinas as an expressive musical instrument:

From Pat Missin:

First of all, it's a little misleading to talk about "the harmonica".
There are quite a few different styles of harmonica that allow the
reeds to function in different ways, allowing for different forms of
pitch bending. I'll give some examples of this later.

The Western style free reed can function in two different modes of
operation. The normal mode of operation is what Helmholtz calls the
"inward striking reed" or what Johnston calls the "closing reed". In
this mode the primary motion of the reed is towards the reedplate and
the note produced is near the natural pitch of the reed - actually
just slightly flat. This is the mode of operation when a blow reed is
responding to positive pressure, or when a draw reed is responding to
negative pressure. In this mode, by altering the resonant pitch of the
vocal tract, player can lower the pitch of the note produced. There is
no fixed limit to the degree of the bend, but the further the reed is
pulled from its natural pitch, the weaker the note produced. In
practice, this sort of bend is most often limited to one or two
semitones, although sometimes they can be bent considerably further.
The physics of this sort of bending is similar to how notes are bent
on instruments like the clarinet or saxophone (see Johnston et al,
1986).

The other mode of operation is Helmholtz calls the "outward striking
reed" or what Johnston calls the "opening reed". This mode of
operation is brought into play in certain circumstances when a blow
reed is caused to responding to negative pressure, or when a draw reed
is caused to respond to negative pressure - ie the reed is made to
work "backwards", with the primary motion being away from the
reedplate. The note produced is significantly higher than the natural
pitch of the reed and by manipulation of the embouchure and vocal
tract the pitch can be bent upwards - again the further from the
natural pitch of the reed, the weaker the note produced.

As I mentioned, the way the various types of harmonica are constructed
in ways that permit or prevent the reeds to operate in certain ways.
The harmonica most closely associated with the blues is the Richter
style diatonic harmonica. With this style of construction, each
chamber contains a pair of reeds - one blow reed and one draw reed.
The typical blues-style bend involves an interaction between the
reeds. By changing the resonant pitch of the vocal tract, the player
can lower the higher note in a given chamber down to a pitch a little
above the lower note. What happens as the bend starts is that the
higher reed [functioning as a "normal" closing reed] vibrates at a
slower rate, producing a flatter pitch. As the bend deepens, the lower
pitched reed starts to vibrate as an opening reed, at a higher
frequency than its normal pitch. When the bend reaches it maximum
depth, the higher reed ceases to vibrate and the note produced is
entirely the work of the lower reed vibrating at a little above its
natural pitch. For example, if a chamber contains a C blow reed and a
D draw reed, the D can be lowered to around C# by draw bending. If a
chamber contains an E blow reed and a G draw reed, the G can be
lowered to around F by draw bending. If a chamber contains an E blow
reed and a D draw reed, the E can be lowered to around D# by blow
bending and so on. Compared with the single closing reed bend, this
type of bend sounds consistently powerful through the full range of
the bend.

The lower note in a chamber of a Richter harmonica cannot be bent by
more than a few cents, but by a similar technique to bending, the
other reed can be forced to operate as an opening reed, producing a
note slightly sharper than the normal higher note in that chamber.
These are called overblows and overdraws (although it should be noted
that some older players used the term overblow to refer to upper
register blow bends). For example, if a chamber contains a C blow reed
and a D draw reed, a D# can produced by overblowing. What happens is
that the blow reed stalls and the draw reed vibrates as an opening
reed at a higher than normal rate. If a chamber contains a G blow reed
and an F draw reed, an F can be produced by overdrawing and so on.
Depending on the skill of the player and the adjustment of the reeds,
overblown and overdrawn notes can be bent upwards in pitch. Using
bends, overblows and overblows, the Richter diatonic can produce a
complete chromatic scale, although timbral consistency is difficult to
achieve due to the various methods used to produce the notes and the
intonation of the bends and overblows/draws is obviously dependent on
the skill of the player. The oft repeated comment that blow bends are
harder than draw bends is rooted in the fact that on a standard
Richter harmonica, the draw notes are higher than the blow notes for
in the first two octaves, with the blow notes being higher than the
draw notes in the upper range of the instrument.

The relatively recent Hohner XB-40 uses a unique construction that
allows blues-style bending on every note of the instrument. Each
chamber is valved to direct the player's breath to a pair of reeds - a
"normal" reed and an auxiliary reed mounted in opposite orientation to
the normal reed. The auxiliary reeds remain silent during normal play,
but come into play during bending, functioning as opening reeds. In
this way, the available bends are not dependent on the tuning layout
of the instrument and overblows/draws are not possible.

Chromatic harmonicas, associated with such players as Toots Thielemans
and the late Larry Adler, are basically two diatonic reedplates on a
single body, tuned a semitone apart, with a device for directing the
player's breath to one or the other reedplate. Each chamber contains a
pair of reeds, one blow and one draw. However, in most chromatics the
reeds are valved which prevents them from functioning as anything but
closing reeds. This allows all the notes to be bent, but the bends
have a different quality to the dual-reed bends of the Richter
harmonica. A good example of valved bends on the chromatic would be
pretty much any Stevie Wonder solo. Depending on the skill of the
player and the adjustment or the reeds , valved bends can be quite
extreme, such as deep bends in The Harmonicats' version of "Cherry
Pink and Apple Blossom White".

Some players have experimented with both selectively removing valves
from chromatic harmonicas and adding valves to diatonics, to change
the available bending options.

There are certain types of harmonica that only have blow reeds.
Sometimes these are in pairs, such of the typical bass harmonica,
which in its most common form uses pairs of reeds tuned an octave
apart. Bending on these is not really possible. Other all-blow
harmonicas have single reeds per note, each reed in its own chamber.
These function as closing reeds when blown normally and can produce
bends like valved reeds. They can also be overdrawn to produce higher
pitches and be bent upwards, although this is not a common technique.

Double reed diatonics, such as the various octave and tremolo
harmonicas are often said to be impossible to bend, although this is
not true - in fact they actually offer more bending possibilities than
the previously described instruments, although these possibilities are
not commonly exploited. The most common double reed harmonicas are
constructed in the so-called Wiener or Viennese style. There have two
rows of holes in the mouthpiece, with each hole leading to a chamber
containing a single reed. By positioning his or her mouth so that only
a single reed is activated, the player can sound it normally, or as a
closing reed bend, or as an opening reed overblow/draw. By positioning
his or her mouth so that both a blow reed and a draw reed can be
sounded together, then a blues-style dual reed bend can be achieved,
with the player being able to bend the higher reed as though they
shared a single chamber.

I'm not sure that much of this is of any direct usefulness to the
concertina player or builder. Tom Tonon's BluesBox uses a variable
geometry chamber to achieve closing reed bends, but I'm not sure how
easy it would be to come up with a way to make accordion or concertina
reeds function as opening reeds. However, there has been a recent
development that may be of interest, the Antaki TurboSlide. This is
based on a harmonica from the German company Seydel, which uses reeds
of stainless steel, rather than the brass or bronze reeds used on most
other harmonicas. A mechanism is added that use tiny powerful magnets
that change the rate of vibration of the reeds, producing bends that
are controlled by the player's fingertip, rather than by their
embouchure. This page features a demo of it by yours truly:

http://www.turboharp...=59&tid&did

There are no conventional bends at all in this piece - all the bends
are produced using the TurboSlide mechanism. It strikes me that a
similar mechanism could be used to bend pitches on the steel reeds of
the concertina, although I should note that Prof Antaki has a patent
pending on the idea.


References:

"The Role of Vocal Tract Resonance in Clarinet Playing" R. Johnston,
P. G. Clinchf and G. J. Troup - 1986 http://mis.ucd.ie/Members/
RJohnst/oldclart.pdf

"Pitch Control in Harmonica Playing" R. Johnston - 1986
http://mis.ucd.ie/Members/ RJohnst/oldclart.pdf

"On the Sensations of Tone" Hermann von Helmholtz, Alexander John
Ellis - 1885 http://tinyurl.com/4q9hdgn

Other works worth reading are listed on this page:
http://www.patmissin.com/ffaq/q35.html



#31 Johann

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Posted 17 March 2011 - 05:48 PM

I never did hear of this pedant with magnets, but i did some tests with this modern tiny and very powerful magnets magnets, and i can tell that it work quite well for bending notes. Dont think that the result is completely comparable with the way tom douse this bends.

The sound i a little bit different, because in case off a maximum bend the resulting overtones are a bit distorted.


Johann

#32 Ardie

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Posted 18 March 2011 - 12:15 AM

I have now read the article "Pitch control in Harmonica Playing" by Robert B. Johnston.

There are several presumptions in it which may be questioned and some rejected by simple tests.

1. "The more complex chromatic harmonica does not readily respond to the technique"

Not correct - known performers do bends with the chromatic and I may do it with the "Chordomonica" which is constructed in a similar way.It is valved, and with the C model holes 3,7 and 11 has got a G both on blow and draw wich can be bent to F# both on blow and draw ( another argument against the "secondary reed" idea)

2.When playing the "classical way"..."The tongue is not available to alter the shape of the vocal tract and pitch bending is not used"

This is taken as an argument to proove the role of the vocal tract but I may do bends with tongue blocking 3 of 4 holes the common way and not changing the tongue position at all.I am not used to the the technique so it is rather tricky but it contradicts the claimed obligatory role of the tongue.

3."B.Only certain notes can be bent - low draw notes and high blow notes"

It is obviously *easier* but not strictly so which contradicts some of the conclusions regarding the role of the "secondary reed"

4. "C. for those notes that can be bent , the pitch can be varied ...down to a semitone sharp of the pitch of the other note in the same channel( which is flat of the note being played)"

Not quite correct.With some difficulty the first hole D can be bent to C and the fifth hole F ( draw)to E and the seventh hole ( blow) from C to B

5. "D.For draw notes the pitch variation is essentially continuous..for a continuous change in mouth geometry"

Changing the "mouth geometry" is obviously not necessary to achieve bends and the experiment in post #24 in contradictory too.

6. "E. Those changes in tongue position from low to high notes are similar to those found in woodwind playing"

This conclusion is not verified as far as I can see

7. "Furthermore our experiments show that both reeds in the channel are involved in pitch bending contrary to the general belief that only one reed is vibrating at any time"

Not correct.See 1. above.

8. "It is in fact found that when one reed of a harmonica is covered by tape the instrument will only sound when certain mouth shapes are assumed.This was also found for the artificially blow instrument with one reed fixed"

The conclusion goes too far assuming that "mouth shapes" being formed by the tongue position are necessary for the bending.The bending no doubt may be achieved without involvement of the major/deeper vocal tract.This is observed while playing where you can do bends either by a tight/narrow "kissing" method or an "open mouth" method.The experiment in post #24 also contradicts the conclusion.

9. The article contains a complex theoretical discussion partly(!) supported by the experimental data but the described interactions between "closing reed" and "opening reed" as far as I can see lack evidence and thus remain hypothetical.

#33 harpomatic

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Posted 19 December 2017 - 10:22 AM

I have a very conclussive proof that double reeded bends do, in fact exist and are constantly used by harmonica players. There are also single reeded bends, a different phenomenon.

#34 ttonon

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Posted 29 December 2017 - 12:04 PM

I have a very conclussive proof that double reeded bends do, in fact exist and are constantly used by harmonica players. There are also single reeded bends, a different phenomenon.

 Hi harpomatic.  Thanks for your comment.  Can you supply me with this proof?  Thanks

 

Best regards,

Tom

www.bluesbox.biz



#35 harpomatic

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Posted 06 January 2018 - 06:10 AM

Tom, greetings! Well, there are two sources of proof, one is my personal one that I will describe shortly, another is out there in the world in form of a harmonica, built around this principle. The first one, the original designed by Rick Epping for Hohner(also a concertina player, if I am not mistaken), called XB40, no longer being produced, and currently the only other that's in production is Suzuki S30 or something like that. The XB stands for "extra bending", and it does that, indeed. That includes bends in holes (reeds) that normally do not bend, all 40 of them. The ones that do not bend normally, do not do so due to the double reeded bending phenomenon that we are discussing here: if an opposing reed is higher in frequency, the note will not bend (down), as you would expect on reeds that do bend.This has long been known to harmonica playes, and was an easy explanation of why harmonica abruptly refuses to bend beyound hole 4, on the draw, as the tuning arrangement changes on the Richter diatonic and blow reeds are no longer lower in pitch than the draw, like on the first 4 holes.Thus no familiar bends on the draw. This also explained why you get the deepest bend on hole 3 -its opposite blow reed is 2 whole tones lower, as opposed to the rest being only 1 whole tone appart. Now, that in itself is a form of proof, that for the past 30 years at least, has been a common knowledge among harp players. Back to XB40 - the harp exploits that phenomenon, by building in an additional "enabler" reed in every hole. Such reed doesn't sound on its own, but only reacts to your bending action, now on every note, every hole, exhale or inhale. That, in itself is another form of proof. Now, the 3rd is my own claim to fame in this department - the deepest bend of the reed, ever recorded. I will look up a link to it, as it was posted on harp-l (harmonica forum) by Zombor Kovich (I think I got his name spelled correctly). Now, I share that claim to the "deepest bend ever recorded" with Zombor, as he actually conducted and recorded an experiment, based on my hypothesis. I am not the inventor of this double-reeded principle, nor am I the first one to discover it. However, surprisingly, when I hypothesised that due to the known principle, we can bend a reed well beyound 3 semitones, possibly down a whole octave (the limiting factor being the opposing reed's pitch) no expert would confirm this. Harp-l is a forum where the biggest and brightet of names in harp playing, construction, history, etc frequent, among all other harp enthusiasts, much like Cnet here, only much bigger). Now, surprisingly noone has ever done just what I hypothesised, and many leading experts said that, although seemingly correct in theory, in practice such a bend would likely be too deep, and likely impossible to achieve. I was surprized that none of the experts, set up with the technical means of experimenting, have tried it yet. I was away from home at a time, unable to conduct the experiment myself. Zombor volunteered to physically conduct the experiment, and produced that wildest of bends, the entire octave down, recorded it and posted on harp-l for all the posterity. Its somewhere out there, done few years ago, I will try to fish it out for you.

Edited by harpomatic, 06 January 2018 - 06:23 AM.


#36 harpomatic

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Posted 06 January 2018 - 06:33 AM

Now, the single reeded bends do exist, as well - you do get them on a chromatic harp, where reeds are isolated from each other via a different construction method, including valves, like in concertinas and accordions. Yes, the single reed can bend down, almost a whole tone, but not much more than that. It sounds very similar, but not entirely the same (not as deep and raunchy), and it doesn't feel the same (in the player's mouth). You can, however, remove valves on an airtight harp (most of them, though not all, you have to know what you're doing there), and those deep, raunchy, dirty bluesy bends become available on a chromatic. Another form of proof of double reeded bending...

Edited by harpomatic, 06 January 2018 - 06:34 AM.





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