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Dana Johnson

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Everything posted by Dana Johnson

  1. It is very likely playing too long at a time in the beginning is the cause of your trouble, though things like carpal tunnel syndrome can be the result. Right now back way off on your practice and stop if it is hurting at all. Different things happen to your body when playing. First, muscles get used in ways they aren’t used to, you don’t need a death grip to have a thumb muscle tensed for hours on end. Also, depending on how you play, one arm may hold its end still while the other moves the bellows. This means one shoulder area is getting isometric exercise while the other alternately moves and relaxes. Nerves can be pinched in the shoulder area from muscular pressure that can be felt in the thumb or wrist or other fingers basically any joint on the way from your neck to your hands can impact your nerves. Slowly building up playing time gives your body time to balance things out. Carpal tunnel syndrome is one of a number of repetitive stress injuries. To avoid it, the tendons that operate your fingers need to pass as close to straight through the carpal tunnel which is like a band around your wrist. Arching your hand back or in the direction of your thumb causes them to press on the band as they move around a corner back and forth when playing, eventually causing irritation and swelling. Holding the concertina too close to your body causes you to angle your hand thumb-wise as well as bending your hand back. Ideally, your elbow should be at an angle greater than 90 degrees which happens when you move the concertina towards your knee. Your arm should make a straight line from elbow to the tip of your middle finger. The closer you get to this, the happier your hand will be. Depending on your concertina’s shape, this may mean rocking it up a little on the corner rather than flat on your thigh/knee. The last thing is to learn to relax your muscles every instant they aren’t being used. like when you stop a note or change directions. If you do this, you’ll find you get much less tired and reduce the pain from maintaining muscle tension. On a duet, try changing direction for phrasing rather than from reaching the bellows limits. Dana
  2. The stiffness of an alloy is defined by its modulus of elasticity, sometimes referred to as Young’s modulus which measures the amount of strain produced by a given stress, where strain is a measure of elongation under stress. This is not the same as tensile strength or yield point which refer to the amount of stress needed to produce permanent change. While tensile strength and yield point increase with increasing hardening of an alloy either by heat treatment in carbon steel or work hardening in brass or other nonferrous alloys, only one number is listed for the alloy’s modulus of elasticity. I once tried hardening a reed of 1095 steel to a temper starting at file hard, where a file would not touch it, and gradually lowering the temper to light blue where it was quite soft, but not really annealed. This didn’t change the pitch (which depends on stiffness) but had a large effect on how easily the reed was to permanently bend or change the set. A long time ago I switched from 1095 steel to the Uddeholm UHB-20C alloy which has as one of its listed uses as accordion reeds and is produced in a somewhat harder temper than the blue tempered 1095 steel. This alloy seems slightly stiffer, and I found that a given profile will have a higher pitch. It also shears cleaner and holds its set better which I like a lot. We normally equate stiffness with hardness but I think that is because most of the stiff things we encounter are also hard. Brass of any hardness is less stiff than any steel. I have a hard time letting go of this myself but if you want to calculate the frequency or amplitude of a reed, the number you use is the modulus of elasticity. If you want to calculate the amount the reed has to bend before it won’t return to its original position, you use the tensile strength yield point. Dave’s remarks about detempering a reed with hot solder are still an issue, though since it only is used at the reed tip where the steel is at its greatest movement but least bending, done properly, it doesn’t influence the part of the reed where it would cause real bending trouble. Regardless, doing no damage to a reed is the goal. especially on old and valuable instruments. You need to avoid heating the reed except where the solder touches it and removing the iron as soon as you see the solder wet the steel. The flux works at the low end of the temperature, and the melting of the solder helps absorb the excess heat that might overheat the steel. I use a Kester brand low temperature silver bearing lead free solder that melts at about 215 degrees C, with a synthetic rosin core (removable with alcohol and non-corrosive residue ) that leaves the underside of the tip at a light straw. It wets the steel very well and stays bright for many years. Please pardon my inability to keep things brief. For me, this is talking shop, so I get carried away. Best wishes to all, Dana
  3. There are a few things to know. Actions on the reed Removing/adding metal are not uniform on the reed. Adding weight at the tip where actual bending is least lowers pitch. This effect continues down the length of the reed though to an ever lessening degree. If we are not talking about solder or other soft metals, then the extra metal starts to increase the reed’s stiffness countering the lowering effect. ( soft metal just damps vibration when it is bent) Removing metal at the tip causes the pitch to rise, an effect that continues down the reed to a lessening degree until the reduction of mass is countered by the reduction in stiffness which has the opposite effect. Likewise , removing metal at the root where bending force is greatest decreases stiffness, lowering pitch. Again this continues to a lessening degree up the reed until it is countered by reduction of MOVING mass. As you can see, there is a stretch roughly around the center of the reed that some refer to as the belly that has little effect on pitch, but does effect the stiffness of the reed. Thinning a perfectly good reed in that area just weakens the reed, reducing its maximum volume and increasing the tendency to choke or blow flat under pressure. For practical purposes, removing metal for tuning purposes should be restricted to about the first and last quarter of the reed’s length. This wants to be spread over that distance to avoid spots that will focus the bending. When designing reeds, the profile ( longitudinal cross section ) needs to produce a reed that is similar in stiffness to its mates. Lower reeds need to be about 70% of the stiffness of the mid range reeds, while higher pitches need to be only 40% or less of the stiffness of the mid range reeds. This is because all the reeds need to speak at very close to the same bellows pressure, but the aspect ratio length/ width and total area of the reeds varies dramatically as well as does the perceived loudness of the different pitches. This variation of stiffness should be a smooth transition from one reed to the next, with each reed falling someplace on the overall curve depending on its pitch. To accomplish this, you adjust the profile so that for a given reed length, the tip is as thin as it can be but still thick enough to keep the overall bending smooth and strong enough not to be vulnerable to damage. The tip has to have enough mass to lower the pitch while the reed still is acceptably stiff. This creates low reeds that are thicker with higher mass at the tip, reducing thickness toward the root to keep the stiffness low enough to reach the lower pitch. High reeds are the opposite being thick at the root and thin at the tip. The mid range reeds are close to flat, but not quite. Flat reeds can work, but they restrict the length parameter in a way that makes low or high reeds Impractically long or short, as well as making it very hard to get a good balance in volume. When designing reed profiles, the “central” section where the pitch raising and lowering effects of metal removal cross, is where you can adjust the reed stiffness without affecting pitch, though as the neutral area is thinned, the neutral center moves toward the tip since stiffness is reduced much faster than the mass is reduced. For a given loss of metal. Generally reeds are never a straight taper either direction and are at least slightly thinner than a straight line would make them in order to keep the stiffness in a practical range. These are the basic principles for reed design to create responsive well balanced reed sets. Individual reed makers will make their own choices that work best in their instruments. There is still a fair amount of latitude here since the stiffness vs mass distribution can produce reeds of a given pitch and length within a range of profiles. I know this is a lot of info and goes well beyond your question, but a number of people from time to time want to adjust their reeds and a good understanding of what is happening can help avoid mistakes. Making reeds by hand is a very practical thing, not some arcane knowledge. I measured my reed stiffnesses with a clever gadget of my own making, but when comparing one reed to another like it, springing them with your fingers will tell you whether one is even slightly stiffer than the other. You can make replacement reeds for yourself if you are careful with a file and ready to make a few bad ones at first. I do most of my reeds on my CNC grinder, but there are a few I make by hand in the lowest notes like G2 and A2 since I use so few of them. Dana
  4. Whatever you do, make sure it (and you ) can survive a spill. I’m not a big fan of soft cases. I know a lot of people use them. They are fine until they aren’t…
  5. Hi Tom, I am not sure what different air oscillation modes a chamber can provide, and I am pretty sure hemholtz resonator is one, like the main body resonance of a violin box, as well as a back and forth sloshing mode where the the pressure alternates ends of the box without air entering or leaving the “f” holes. There is also the question of how the reed itself alters the hemholtz frequency. Calculations for ideal resonators must have to be modified when for instance, the chamber has flexible walls ( lowering the frequency. ) Your experience of the reed being killed when the resonator matches the fundamental (or any strong harmonic ) is what I expected. You are right about being able to alter a balky reed’s chamber to get it going properly. On My Wheatstone Layout G/D there is a pad that opens onto a chamber with 2 reeds that are of substantially dissimilar lengths. I found the small one of the reed pair was much quieter than it should have been compared to reeds of similar pitch in other chambers. I split the chamber into 2 sections and the reed immediately was at its proper response and volume. Note that the drastic change in chamber volume had no noticeable effect on the either reed’s tone compared with other reeds at those pitches with full width chambers. ( the reed in the short side is a press reed so is not visible. The split chamber allowed me to dispense with the valve for this small reed where without the partition, it needed one. This idea of resonances interfering with the reed vibration is something I have generalized, with absolutely no proof, to the notion that the body of the concertina behaves like a filter, suppressing or reducing the various components of the reed’s spectrum. Hopefully you will be able to get as close as possible to an isolated reed without the complications of chamber volume. You might need a good anechoic ? chamber to do your tests in because normal rooms can have a surprising number of resonances that can cause trouble. If you need other reeds, I’ll be glad to help if I can. Best Wishes, Dana
  6. I make Wheatstone style bellows where the binding goes on last, I skive my runs down to zero at the edges over about 6 mm of width. With the binding being 18mm total. Coupled with the opposite shive on the edges of the leather butterflies, (leather, not papers ) this leaves a pretty level surface. Where the skived surfaces overlap. For the rounded corners, I cut the ends of the pleats on a shallow angle leaving a v shaped notch at each peak end. The angles are such that combined, they form a segmented arc. The split at the ends comes together when I put the gussets on and fold a little skived excess over the top. Once the gussets are on, the bellows is air tight, and the binding only serves as protection and a cover for the card edge which I also cut with s 45 degree mat cutter so the card thickness at the peak is zero, helping to reduce the need for the leather to stretch when the bellows is closed. The wider your binding strips, the more material on the side you have to try to smooth out, so don’t think wider is better. When I wrap my binding, I use a bit of wet sponge to wet the binding a bit where it goes around the corner. That lets that portion of the leather stretch there only while allowing you to put more tension on the strip ahead of the corner. This helps since your strips cut parallel to the spine are goat’s least stretchy direction (belly skin excepted) , leaving its natural stretch across the peaks where it helps to reduce the bellows stiffness. The wet at the corners allows just that part to stretch, pulling down the edges at the corners nicely with little or nothing to smooth out. Dana
  7. Tom, I don’t consider a reed that fails to speak due to chamber length mismatch, “choking”, what I experience as choking comes from a reed that speaks fine at lower pressure, but stops abruptly if the pressure passes a certain point. I experience this in two cases. First is when the reed is set too low, which may decrease the starting pressure ( seemingly a good thing but limits you to quiet playing ). Second is when the reed is weak for its length ( incorrectly profiled in the neutral area ). These reeds will choke regardless of set. I wonder about the hemholtz resonator analogy. I am not sure how this works since the chamber is open at both ends, though one end changes as the reed moves. Is resonance the only characteristic a chamber can have? Also, in the G1 chart, the bold numbers are for the 15th harmonic which is going to be vanishingly small, and I have a hard time seeing that as killing the vibration. I wonder if electrical analogies like capacitors and inductors might be in play, since both the reed and chamber can be energy storage /modulating devices. , and not necessarily as a tuned L/C circuit. Maybe a power factor phase shift ? In my experience, varying the height of chamber walls affects the proportions of the harmonic spectrum , with shallow chambers favoring higher harmonics over fundamentals. Length did not affect this noticeably. ‘even .032 inches in height difference is very noticeable in tone difference.
  8. Lukasz, especially for lower reeds (B3 and lower) and especially if the press and draw reeds are close in pitch, ( and or have a harmonic component near the paired reed ) I often experience an odd coupling where the flap valve adjacent to the active reed slightly opens and closes causing a burr adding to the reed pitch. This also happens at low to medium pressure when the valve is cupped ( touching at tip but not in center ) even for high reeds, where it opens and closes with the pressure variation, making the burr related in frequency to the active reed. I can usually solve the low reed condition by using a valve that is thicker but not stiffer so it has a lower ability to vibrate at the activating pitch. The noise isn’t valve noise, but rather how the driving pressure on the active reed is caused to vary by the slight bypass of the vibrating valve. I don’t know if this will help your particular case. Dana
  9. I have similar experience to Lukasz, though the longest reed I make is G2. I have also found reeds around C6 and above can actually go sharp at the higher practical pressures. Here, I haven’t seen more than +5 cents. Lower notes are more affected, and quite audibly so, enough to be made part of technique. Here, I do find that press works too like draw, but you have to mean it. When tuning, I find it important to keep pressure constant since it easily affects reeds in the 3-5 cent range at normal playing pressure The big thing Lukasz mentions is the effect of chamber length as its proportion to reed length varies at different pitches, and the pad hole size in conjunction. On a C/G Anglo, I use 4 different hole sizes. ( 5 on a G/D ) because not only can a too small pad hole flatten the note, but it also causes a tone change where higher harmonics are reduced. Wheatstone Linotas I’ve seen have relatively small pad holes and the tone change from exertion while playing is something I’ve heard Noel Hill use for effect. there seems to be a best size for different pitches, though it probably interacts with chamber length, so may not be transferable from one chamber layout to a different one. I originally used one size for everything, but found by progressively reducing the diameter, I reached a point where smaller would actually make the note sound clearer, but still be large enough to prevent the tone change at high pressures. I used that break point to size all the holes. The Wheatstone Duet I used to own had equivalent pad hole scaling (and chamber length scaling ). I do not understand how chambers and tone holes work, but a low reed un an undersized chamber may not operate at all. My tuning block has a series of separate chambers sized for pitch ranges. I switch chambers when a reed starts to be balky or not speak well at a particular chamber. The effect of the chambers / pad holes is large, and trying to tune a reed in an environment where it is clearly getting damped compared to a reed that goes well with the chamber can easily mean 10 cents off what it should be. I use little rubber sheets to cover the tuning ports not in use, and can have a balky reed sound good again by partially opening an unused port. Since I tune at a constant pressure, I am guessing that opening the free port, changes something in the acoustics. The chambers all share a common plenum and all have the larger pad holes emptying into it. one thing I wonder about is the way air moves into or out of pad holes. Air going into a hole looks like water going down a large drain, coming in from the sides as much as above, while air leaving a hole is more jet like. the proximity of the pad to the hole may cause different effects on the press vs the draw because of the relative obstruction of airflow. one last thing, poorly centered reeds are much more vulnerable to flattening audibly as pressure rises, as is a weak (thin ) reed for the given pitch. Sorry not to have a lot of hard data, but given how interactive things seem, it would be easy to misattribute any particular effect. You are going to have to build your own setup where you have more control than I do, where I try to find what gets the results I want without trying to figure out why. Best Wishes, ‘Dana
  10. After tuning 6000 reeds, I am inclined to agree with Alex, with the exception being that the flattening on raising or sharpening on reducing the set depends a lot on the length of the reed, with longer reeds being less affected than small reeds. I re set a G6 reed on a friends concertina that was set ( probably at the factory ) so high it took a ton of pressure to sound at all. When set to the proper height where it responded quite well, it was 20 cents sharper and needed to be retuned. In most cases for reeds that are responsive, I generally don’t see more than a couple cents variation. I always check the set before any tuning and often find that returning a reed to its proper height is often all that is needed. Given the number of things that can affect pitch, the reed isn’t always the culprit.
  11. High humidity causes less problem than low, but your description is a common one. The reed pans can absorb a few grams of moisture, which will change the interaction with the reeds in a noticeable way. The valves also take up moisture and can lift slightly as the lower layer of the leather expands more than the upper. This can lower response as the valves take longer to close. Nothing to worry about, Dessicants get used up quite quickly and need to be restored by heating in an oven, though most packs I’ve seen aren’t packed to be reused. Unless your case is airtight, the “partial pressure of gasses” will always seek to equalize the humidity between the case and free air. Dehumidifiers are more constant, but use a lot of electricity and still need to be in a closed room. The good thing is that wood loses moisture at a much higher rate than it takes it up. Days vs hours. So it does little damage. The best thing to do is play the thing, which can free up sluggish bits and help them find a stable position. Dana
  12. Hi David, It has been a really long time since I had that duet, but it’s low note was the same as the low note on the 67 button McCann. The right side went down to C4 originally but because of the music I wanted to play, I added notes town to G3. That made for a very full reed pan. Even in that large format, I couldn’t have added extra notes unless they were inboard. The lever arrangement was difficult enough with all those notes. It used all long scale reeds, so going short on the lower notes would help with the relative volume. If you will remember it was originally the same model as that Wheatstone McCann that that fellow with the operatic baritone voice who played McCann at the early NESI years had. His name escapes me. That thing could roar!. (And so could he) For other makers, that Duet had tilted reed pans so the highest notes had shallower chambers and the lowest were deeper. Both sides were like this, but on a more limited range would be less necessary. It did mean that you had less flexibility with reed placement when thinking about lever patterns, but it was important.
  13. I don’t know if you would consider it a deal breaker, but below G3 reeds get bigger fast. Not only that but the chambers need to increase in length over and above what the reed frame would need in order to respond well. For low reeds this means chambers that take up a lot of space. Weight will be more the result of the larger overall size instrument needed to accommodate the larger reed/chamber space on both ends, rather than the weight of the bigger reeds. 30 years ago I converted a Wheatstone 67 button McCann into a 63 button Hayden. The right side was similar to yours except for having a C6 and D6 on the top row, but the left only went down to C2. This was a large instrument, something around 9 inches across the flats, and believe me, there was no extra room. It didn’t include your F#2 or G#2 on the left hand lowest row. The other issue is volume balance. On extended range instruments, the lower notes are much louder than the higher ones which is ok for melody where you can vary your playing pressure to suit the note, but playing left and right together can be a problem since one bellows pressure applies to all the reeds being played. Wheatstone tried with only small success to quiet the left hand by having a much smaller fretwork on the end with the pads being covered by solid surface of the end plate. Lastly and least important, on equal tempered instruments the only difference between D# and Eb is what you choose to label them. Sharps and flats are musical conventions telling you where a note is relative to the home key. The distinction does matter in other temperaments where the “ideal” ratios to the home note are the goal. One of the beauties of the Hayden is the ability to maintain fingering between any key which is asking for equal temperament unless you want to restrict yourself to only a few keys. Dana
  14. Especially if you want to play the genres you mention, having more key flexibility is a must. 30 buttons are fully chromatic for most of their range, but getting fluent in a number of keys will require diligent practice. However, if you organize your practice around that goal, it will become much more natural as you get to associate certain pitches with their buttons ‘ direction. One good exercise is to play something in your normal key, then one whole note up on through some sequential keys. You can do half steps too. Remember, you still have to place the music in the instrument’s range. That means if you find a tune goes too high, play it an octave lower etc. likewise if it goes below the chromatic range, you may need to try it an octave higher. A lot of tunes are in the keys they are commonly played in because they were composed on instruments of a specific limited range. Remember, you will have a number of buttons that play the same note, sometimes in different directions. Try using alternates to find the best to use for each key. Lastly, learn some pieces that are a challenge and need the chromatic scale. I like JS Bach partitas for solo violin since the range is about right for a C/G 30 button. You might need to transpose the music to fit the notes you have available. Even if you don’t master them, they will improve your ability to find notes when you need them. Oh yes, even if you read music Jams/sessions are aural things. You need to be able to hear a note and then play it. Whatever you do, make it fun! Dana
  15. Having 2 mics pointed at each end seems logical, but unless they are quite close, or you are in a fairly well acoustically damped room (or outdoors ) the distance between the mics can cause very noticeable comb filtering, as both mics pick up sound from the other side slightly later than the closer mic. ( causing interference of sound waves that happen at frequency multiples of the separation distance 1x2x3x etc.) Center location in front keeps things equal and having a coaxial x/y mic preserves the stereo aspect without comb filtering. Listening through headphones connected to the mixer or monitor lets you hear what other people are hearing or you are actually recording. Without them, you are not likely to hear what is happening at the mics. Even good mics can be blamed for poor fidelity that really is the result of comb filtering.
  16. I am really not sure, but I’d guess the point of the “ Anglo system “ was being able to increase the number of notes available in a workable size. Reeds are the most expensive part of a concertina and having each button/reed chamber play 2 different notes rather than one substantially increases what you can pack in a small package. A 48 button treble English has 96 reeds while a 30 button c/g Anglo covering a slightly larger range only has 60 reeds. Diatonic free reed instruments have been around for quite awhile, and I expect that their adoption in folk music was driven by low price first and that playing styles evolved to turn it’s restrictions into advantages. The common Anglo with a center row in one key and the inner row a 5th higher, does have rows that make playing in those key easily accessible to beginners. But that layout generates many duplicates in either the same direction or the opposite. This allows you to choose how to play a certain passage or organize your scales to provide better bellows control, ease of fingering, or my favorite, phrasing. Having a “go to” basic scale fingering to start with be it cross row or along the row, gets you up and running, but it is important to get fluent in using the alternate buttons to make the most of the instrument. There are hoards of tunes I play that I will use one button in the first go round of the A part, but use the opposite direction note the second part around because the ending note of the first time through phrases better with a different direction note to repeat. Getting used to using alternates when they improve the music and being able to swap them out on the fly depending on your mood in the tune really can improve your playing. Using alternates when looking for a particular harmony is a great thing to explore, and you shouldn’t consider any basic fingering as more than a starting point. The instrument is remarkably versatile and working out how to best express the music is the path toward real musicianship.
  17. When I was a kid, I was told that you only used the stalks of the rhubarb not the green leaves because that is where the oxalic acid was. ( Checked in the encyclopedia )Many plants use this sort of distribution to discourage critters from eating the leaves. The stalks below the leaf have little if any oxalic acid. Potatoes are similar in that the potato is fine unless very green from light exposure, but the rest of the plant including the fruit contain solanine, a toxic alkaloid. Sometimes it is the other way round as I discovered when our young dog discovered the bulbs of some of our hyacinths were great fun to mouth and toss around. This time toxic to critters underground. We had to dig them all up☹️
  18. When The Button Box first started making the Ceili, Rich seriously considered adding weights to it because compared to other concertinas, it was so light. Just as well they decided to see how people liked it. The rest, as they say, is history. Dana
  19. Even though 20 button’s only completely cover the 2 major keys and their relative minors (Amin and E min for a c/g), you can still play a lot of tunes in D for instance which is only missing the c#. Some tunes really can’t do without that note, but for many others, you can simply hold the previous note or substitute an ornament or chord for the duration of the c#. In Irish trad music, there are a lot of D tunes that leave out the C# presumably because they were composed on instruments that are like harps without sharping levers or one row melodions. Some great players like Jacqueline McCarthy played on 2 row C/Gs. Also, and I expect for similar reasons, Irish music is full of tunes that are “modal” and sound like they should be in D, but partake in the key of C (one whole tone down ) when a C# isn’t available. This mode is so much a part of ITM, that you won’t ever run out of “D”tunes. The same thing holds for many modal A tunes that oscillate between A and G scales. 20 buttons may be more limited than a 30 button instrument, but not as much as you might think.
  20. 2 more little things. Lower reeds that are thin (and don’t have enough strength) may respond well, but are more subject to choking and also blowing flat under pressure. Badly centered reeds also blow flat more easily than well centered ones. Reeds need to develop enough spring force to return effectively against the playing pressure. In instruments like large duets, baritone and tenor Englishs need longer reeds in the mid range to compete in loudness with the naturally large, long and loud lower reeds, so the scale for baritone or tenor may be longer for the same pitches than a treble instrument. Making the already slow low reeds thick heavy tipped to lower their pitch will make them respond poorly, so compromises need to be found elsewhere.
  21. It is very possible to make two reeds of substantially different lengths that are still the same pitch. At the high end say C6, shortening reeds makes a big difference in pitch, so reeds that, as a practical matter, work as they should, end up very close to the same size. However lowering pitch by adding length creates reeds that in the lower notes C3 etc. get long fast and take up more room. In order to keep lower reeds a workable size in a concertina where space is at a premium, shorter lower reeds are chosen and then weighted near the tip either by grinding the reed to be thick at the tip, and or adding solder or a bit of brass to the tip making them heavier and slower to vibrate. The more this needs to be done, the worse the reed’s response. By varying the scaling of the reeds ( the scale factor of length from one reed to the next in pitch ) reeds can be made to fit in a limited space. “Long Scale” reeds are made as long as practical in the low end and generally will be longer pitch for pitch than instruments that needed shorter reeds in the low end. Reed length and width do have an effect on tone, but a lot of other factors do too so it is hard to generalize about causes. Within practical parameters though making a reed longer with a thinner tip will make a more responsive reed. Regarding tone, the shorter chambers that go with shorter reeds have a noticeable effect on tone which may be interpreted as coming from the reed instead of its local environment. Low reeds are naturally slower to respond than higher reeds ( assuming a well made instrument). Optimizing low reed response is a very worthwhile goal since reeds need to equal the music they are asked to play. Dana
  22. It isn’t the number of posts, but the quality of them that counts🙂
  23. If the leather is actually white and not very light blue grey, it is probably alum tanned or tawed. It was commonly used in concertinas in the past and you’ll find many vintage concertinas of good quality that used it. It has the benefit of being quite springy for its thickness without being stiff or heavy. The big problem with it is that over time, it corrodes the brass of the reed shoes next to it. I discovered this on one of my instruments back for tuning after about 10 years and noticed the corrosion only on the reeds next to this kind of valve. Haven’t used it since. Here’s a pic of a Wheatstone tenor reed pan with the original white valves. You can see the corrosion primarily next to the valves, but spreading a bit from there.
  24. “My guess is that the curled up reeds prevent some of the high vacuum pressure from occurring inside the bellows by allowing some excess air flow through non-sounding reeds. This prevents too a vacuum pressure that would tend to choke the reeds that are intended to voice. If those reeds weren't so leaky in the first moments, perhaps the playing reeds would choke and not play at the right time. So we want maximum dynamics in volume, but don't want to choke the reeds.” In my experience, reeds that are set low enough to risk choking under either rapid pressure gradients or high pressure, are set too low to reach the amplitude they are capable of, though they may start at lower pressures. I don’t know if bandoneon makers use a different sort of reed plate window than is found in ordinary accordions. The pictures I have seen look like basic accordion construction except using single plates with a whole row of reeds on them. (More like a harmonica) The pictures I have seen had valves lying flat. Reeds that are very flexible for their pitch also can choke easily, but can’t reach the volume of a reed stiff enough not to choke at its optimal set. Allowing some bypass air can help avoid choking on a reed prone to it. Noel Hill once mentioned needing to slightly feather the air valve when playing a specific note on one of his instruments to avoid it choking. His playing can demand a lot from the reeds (and hand straps! ). On concertinas, a valve that is curled a bit or just bent high, significantly affects the speed of response, as well as causing a noticeable increase in volume as soon as the valve closes. High set reeds can also be slow to start, but the slight delay and abrupt increase in volume shortly after the reed sounds, is a dead giveaway for a raised or curling valve. Dana
  25. There are a lot of tunes in ITM. That seem to have been built for along the rows playing. I figure perhaps they came from the melodion players. They organize themselves beautifully around the push pull nature of that kind of playing, matching good phrasing and rhythm, as opposed to other tunes that chafe at being forced into that restriction. C/G’s are very versatile given their pitch range which is similar to a fiddle and covers all the notes typically found in the whole ITM repertoire. The common ITM keys are very easily learned on a C/G.
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