Question For The Experts

[Hooves]

Hello again oh ye agile gods of the twisted digits,

 

I have a question about reeds: from everything Ive read so far on how reeds actually produce sound, it looks like a single reed can sound in both directions of air flow if the reed is centered in its pan. So, in English concertinas, of which I have only one with accordion waxed reeds, there are 2 reeds per button, one for each bellows direction, but it seems like it should be able to still work with just one 1 reed.

 

I could be misunderstanding what is happening with the reeds.

 

Perhaps its so you don't have a pause when changing directions, forcing the reed to stop and then sound again as the air changes direction. That makes sense to me.

 

Are or were than any English system concertinas built with a single reed for each button, other than eraly prototypes?

[m3838]

Hello again oh ye agile gods of the twisted digits,

 

I have a question about reeds: from everything Ive read so far on how reeds actually produce sound, it looks like a single reed can sound in both directions of air flow if the reed is centered in its pan. So, in English concertinas, of which I have only one with accordion waxed reeds, there are 2 reeds per button, one for each bellows direction, but it seems like it should be able to still work with just one 1 reed.

 

I could be misunderstanding what is happening with the reeds.

 

Perhaps its so you don't have a pause when changing directions, forcing the reed to stop and then sound again as the air changes direction. That makes sense to me.

 

Are or were than any English system concertinas built with a single reed for each button, other than eraly prototypes?

 

There were accordions with the system, that maintains same direction of air flow, regardless of bellows movement. They have only reeds, singing in one air direction. The benefits of this is continuos, organ-like sound, but the weight and cost is prohibitive.

There were also single reed systems, where the reed tounge is mounted on the cylinder roll. When the reed is moved along the roll, it changes it's pitch. The benefit was smooth continuos change of pitch.

I think Indian reed organs have single air direction and valves, redirecting the air inside.

They still produced today, and I have only seen brass reeds.

I'm not sure the reed, sitting in the middle of a metal plate, will sound at all, but I'm not an expert.

[Dana Johnson]

it looks like a single reed can sound in both directions of air flow if the reed is centered in its pan. I could be

misunderstanding what is happening with the reeds.

Free reeds of the kind used in accordions and concertinas only function in one direction. There are as mentioned, ways to redirect the air flow so it always enters the reed from the same side. ( I used to experiment with this ) But the reed still works the same way. It relies on the extra little kick it gets from the gap ("Set") between the end of the reed and the reed plate surface when the air flow under and by the reed which acts more strongly than the mere pressure of the air against the reed which after all works in opposition to the reed half the cycle. It is kind of like having your mom or dad push you on a swing before you learned how to pump. A reed centered in it's plate or a reed that is mechanically set in motion will not continue to operate even if airflow is maintained without the initial above neutral position or some equivalent "kicker".

 

Interestingly enough, the ancestor of the free reeds, the chinese Sheng, uses flush reeds (made from the reed plate itself ) and existed as far back as at least 770 B.C. It uses tuned resonator tubes with the reed mounted at the base of each tube in a wind box to provide the kick at the resonant frequency and is happy to operate in either direction (suck or blow since it is played with mouth air pressure ). The reeds are incised from the back of the bronze plates till they are nearly all the way through and then the finish cut on the otherside makes a perfect fit. they are "profiled" on the back side and are often weighted on the tips, and any extra gap between the reed and the reed frame or plate is filled with a paste mixture of powdered marble and copper rubbed onto the face of the reed plate.

 

As a reference to the required length for the resonant tubes, they are effectively the length of a set of pan pipes of the same pitch and in a modern orchestral version can be quite long, resembling more a cross between Uillean pipe regulators and an arthritic squid. Modern ones even are keyed. the neat thing about them is that with the side hole in the pipe open, the reed doesn't play ( resonant condition defeated ) but as soon as the side hole is closed, the resonance of the tube is recreated and the reed sounds. It is the opposite ofall the other wind instruments I know of.

 

I know there have been plenty of attempts at making double acting reeds, but none sucessful enough or easy enough to make to compete with the single acting ones.

Dana

[Richard Morse]

Actually, a reed centered in a frame of the typical thickness that accordion and concertina reeds use wouldn't sound at all - in either air direction. It just won't start. Perhaps if it were started somehow it would continue to sound until the air pressure diminished (or stopped, like for a bellows reversal). The reason why English concertinas have two reeds per button is so that one would sound with the bellows forcing air one way and the othe would sound for the other direction.

 

I don't know of any concertinas that were produced with reeds sounding in both direction though I've seen and played an accordion like that. There didn't seem to be much benefit with those double acting reeds though as they were the same size as the standard reed (plate assemblie)s and the double acting reeded were used only for about 90% of the treble notes. The highest notes and bass side notes were standard single-action reeds. I have no doubt that they were more expensive as they looked pretty complicated with multiple parts to the frames.

 

I've heard that there are some instruments (shengs and similar?) instruments that have reeds fashioned *with* the frame - both are one piece of material (usually wood) or grass), and that they sound with both air directions.... but know virtually nothing about them!

 

-- Rich --

[Stephen Chambers]

There are as mentioned, ways to redirect the air flow so it always enters the reed from the same side. ( I used to experiment with this )

As so it seems did Charles Wheatstone, at least it's in his 1844 Patent!

 

But I suspect that it never went into production because it would have been complicated to produce, and would need plenty of maintenance to keep it working properly.

Edited October 19, 2006 by Stephen Chambers

[Dana Johnson]

I've heard that there are some instruments (shengs and similar?) instruments that have reeds fashioned *with* the frame - both are one piece of material (usually wood) or grass), and that they sound with both air directions.... but know virtually nothing about them!

 

-- Rich --

Here is a short clip from a modern Sheng player, Astounding virtuosity only hinted at in this short section at the beginning of this piece entitled weaving Fishing nets. If you can find the album this is on in a chinese music store, buy it!

sheng_sample.mp3

[Hooves]

I was thinking of a reed I had seen that was a triangle cut in a single piece of wood, where the reed was as described "flush" with the reed plate.

 

I found this web page with some information on "idioglottal" vs. "heteroglottal" reeds, the first being the flush kind, and the other the ones we see in the concertina and accordion.

 

http://www.patmissin.com/history/whatis.html

 

The article mentions the need for a resonating chamber for the idioglottal reed.

 

Thanks for all the additional information.

[Robin Madge]

So, would you in theory be able to sandwich a reed between two reed shoes, top and bottom with a slight gap from each, in such a way that it could start in either direction? Or would the amount that the reed moves mean that it would then become "choked" bty the presence of the other reed shoe?

It wouldn't cut down on the weight a lot but it might mean less space taken up on the reed pan.

 

Robin Madge

[malcolm clapp]

I think Indian reed organs have single air direction and valves, redirecting the air inside.

They still produced today, and I have only seen brass reeds.

 

 

I have worked on many Indian reed organs/harmoniums, but those I have seen only have a bellows at the rear filling a reservoir, so the air flow through the reeds is always in the same direction, as with western harmoniums, American organs etc.

 

Now, if we could somehow mount a reservoir into a concertina or accordion and use the bellows motion to do no more than fill this reservoir....

 

Maybe an external airbag allowing the bellows to pump air into it and also a controlled flow from the airbag to the reeds...

 

 

Hey, we have keyed bagpipes!!!

 

Oh well, back to the drawing board.

 

MC

 

(I really shouldn't drink this stuff...)

 

 

Edited in the cold light of day for spelling "reservoir".

Edited October 20, 2006 by malcolm clapp

[Dana Johnson]

So, would you in theory be able to sandwich a reed between two reed shoes, top and bottom with a slight gap from each, in such a way that it could start in either direction? Or would the amount that the reed moves mean that it would then become "choked" bty the presence of the other reed shoe?

It wouldn't cut down on the weight a lot but it might mean less space taken up on the reed pan.

 

Robin Madge

When air enters a hole between two areas of different pressures, it does so primarily from the sides while it exits as a stream that then diverges. Mounting two reeds like that blocks like that really would need the air entering from the center gap in order to produce the same effect on the reed. I believe some of the designs for double acting reeds have had a special port near the reed tip to let bleed air in to facilitate starting. I actually tried almost exactly the thing you suggested many years ago with no success. (perhaps I should have continued trying ) Doubling up on the reed shoe ends up not saving much but a little space. The work involved is essentially the same. I always thought of double acting reeds as primarily a cost saving venture, since you can really accomodate plenty of notes on existing instrument formats. The expense of the reeds is such a large proportion of the cost of the instrument that being able to do without half of them would be a boon (if they cost no more)

Dana

[m3838]

The expense of the reeds is such a large proportion of the cost of the instrument that being able to do without half of them would be a boon (if they cost no more)

Dana

 

If so, why then not approach it from other direction and improve single action, when it sounds on the pull and gulps the air on the push? Or vice versa? When I proposed my idea of modification, the responce I got was that English is such a perfect instrument, it doesn't need improvement.

Seems to me, adapting to single action playing is easier then designing double action reed or redirecting the air inside a concertina.

 

Another note, I remember seen photographs of a large single action Wheatstone concertina, probably duet, where reeds were secluded in special cylindrical chambers. I think the idea of making it single action came from impossibiltiy to fit all reeds into it.

[DavidFR]

If so, why then not approach it from other direction and improve single action, when it sounds on the pull and gulps the air on the push? Or vice versa? When I proposed my idea of modification, the responce I got was that English is such a perfect instrument, it doesn't need improvement.

Seems to me, adapting to single action playing is easier then designing double action reed or redirecting the air inside a concertina.

 

Another note, I remember seen photographs of a large single action Wheatstone concertina, probably duet, where reeds were secluded in special cylindrical chambers. I think the idea of making it single action came from impossibiltiy to fit all reeds into it.

I think I've seen or heard about a number of vintage single-action bass English concertinas, where the reeds are just so large and suck so much air that you only play on the push, then break and expand the bellows for another go.

 

This could be fine for a bass instrument especially in a band setting playing mainly chords or accompaniment, but would be very detrimental on a melodic instrument since I imagine the bellows expansion would be a heavily interrupting event.

[Theo]

Now, if we could somehow mount a resevoir into a concertina or accordion and use the bellows motion to do no more than fill this resevoir....

 

Maybe an external airbag allowing the bellows to pump air into it and also a controlled flow from the airbag to the reeds...

 

Hey, we have keyed bagpipes!!!

 

Oh well, back to the drawing board.

 

MC

 

(I really shouldn't drink this stuff...)

 

Do you mean like this:

 

And all we had been drinking was green tea!

[malcolm clapp]

Now, if we could somehow mount a resevoir into a concertina or accordion and use the bellows motion to do no more than fill this resevoir....

 

Maybe an external airbag allowing the bellows to pump air into it and also a controlled flow from the airbag to the reeds...

 

Hey, we have keyed bagpipes!!!

 

Oh well, back to the drawing board.

 

MC

 

(I really shouldn't drink this stuff...)

 

Do you mean like this:

 

And all we had been drinking was green tea!

 

Incredible!!!!

 

Green tea for inspiration it is....

[David Barnert]

I think I've seen or heard about a number of vintage single-action bass English concertinas, where the reeds are just so large and suck so much air that you only play on the push, then break and expand the bellows for another go.

 

This could be fine for a bass instrument especially in a band setting playing mainly chords or accompaniment, but would be very detrimental on a melodic instrument since I imagine the bellows expansion would be a heavily interrupting event.

Someone had one of those at the NE Squeeze-In a few years ago. But instead of an air button it had large air holes with flap valves so the bellows could be refilled in a hurry with a quick expansion.

Now, if we could somehow mount a resevoir into a concertina or accordion and use the bellows motion to do no more than fill this resevoir....

 

Maybe an external airbag allowing the bellows to pump air into it and also a controlled flow from the airbag to the reeds...

 

Hey, we have keyed bagpipes!!!

 

Oh well, back to the drawing board.

 

MC

 

(I really shouldn't drink this stuff...)

Do you mean like this:

And all we had been drinking was green tea!

But where are the bellows? All I see is a vacuum cleaner type air pressure source (bottom left corner), and the fan is probably louder than the instrument.

[PeterT]

Someone had one of those at the NE Squeeze-In a few years ago. But instead of an air button it had large air holes with flap valves so the bellows could be refilled in a hurry with a quick expansion.

This reminds me of Bernard Wriggley, at Beverley Folk Festival (UK) many years ago, describing his single action Bass English "It has holes in the bottom; but don't we all?".

 

Regards,

Peter.

[Theo]

But where are the bellows? All I see is a vacuum cleaner type air pressure source (bottom left corner), and the fan is probably louder than the instrument.

 

In an earlier version we had bagpipe bellows, elbow operated, but that ws all a bit much to control, so opted for the vacuum cleaner, and yes it was too noisy, and the air pressure was too high. Don't expect to see them in the shops any time soon.

[Robin Madge]

I did once come across a "piper" with a cassette player concealed in the bag.

 

Robin Madge