Squeaks and Squawks

     It's an amazement to me that after being in the woodwind instrument repair  business for over 50 years I'm still presented with problems, virtually on a daily basis ,that I've never come across before in all that time. Keeps you on your toes I can tell you!!

     There are however a number of problems which are and have been present all the time but which I think are not widely understood & are accepted to be the norm by players and therefore not addressed, the most fundamental of these being the sealing (air tightness) of the tube which constitutes the musical instrument.

     Let me first just go off-piste for a second to explain that I probably come from a completely different place from you dear reader. I suspect that most people will regard their instrument as a work of art, it having the ability to stir the soul and give so much pleasure, a precious thing of beauty etc. I’m afraid I start off from the other end of the spectrum i.e. it’s just a tube of some sort with a few holes in the side. You see repairing instruments is well upwards of 80% mechanics. It’s not the repairers’ business to get emotionally involved, that’s for the player to do and the repairer and maker to facilitate. Put another way, whilst music & the making of such is almost 100% subjective, the manufacture & repair etc. of the instruments which produce it is on the other hand almost all objective!

     Which means most of the following is not my opinion –  it's a demonstrable fact.

     So getting back to this most fundamental sealing of those holes in the tube it must be realized that the majority of faults are as a result of something causing the leakage of air from the wrong or unintentional place on that tube, be it a torn or missing pad or a key being bent or not working correctly. However, it's not that kind of leakage which concerns me here. That's easily sorted. No, it's that tiny amount from each key on what appears to be a perfect instrument, which incidentally also includes brand new instruments as well. You see no instrument is 100% airtight. In engineering terms the keys are not perfect valves. To be so they would have to be a proper metal to metal valve as in a car engine (very noisy) or screwed down like a tap or radiator valve (impractical).

     On top of this it's my experience that in the repair of musical instruments it's more often that too much attention is given to how good it looks and not enough to how well it functions.

A simple and very common example of this would be the replacement of an old worn-out looking pad with a new one which doesn't seal the hole any better than the one it replaces – but it looks better! Or perhaps it's damaged keywork which is now repaired, works well and looks like new again – but doesn't seal the tube properly.

     So let's just say again (and I'm going to keep banging on about this)! It's the cumulative effect of a very small amount of air leakage from each key which has a gross negative affect on playability. It even extends to instruments with open holes like clarinets and open–holed flutes and of course those early ones with no keys at all. You see your fingers leak that small amount just like the pads because they are made from the same thing i.e. a resilient material covered by animal skin!!!

     For the saxophone (and flute) and to a lesser extent the clarinet there’s a further complication to this.

The sax consists mainly of a row of normally open keys, and pressing just about any one of those keys depresses yet another one or two at the same time. Those 2 or 3 keys must hit their respective tone–holes exactly at the same time (that’s called regulation) – and they don't. It's not possible to get them to close at the same time if they don't close individually correctly on their own and they don't because the materials from which they are made (sheep's back and felt on the sax or sheep's intestine and felt on the clarinet) have independently and individually moved and swollen through moisture and temperature changes etc. You see, the pads have been put into the instrument, and with the help of heat and pressure a 'bedding ring' has been ironed into the leather in order to get them to seal exactly so they can be regulated to operate together. This is just the same as ironing a crease into a garment– and what happens to a crease in a garment? - after a short while it partially comes out (how far depends on the material). And if you blow cycles of warm damp air past it, it comes out even faster! And incidentally pushing one of those woolly 'pad saver' things down your saxophone speeds up the process no end!

It's also why for instance, if you put an instrument you don't use very often under the bed for a month or so, when you get it out to use it again it's not the same as when you put it away. In just doing nothing that crease will fade too.

It's one of the major issues affecting, in particular, the majority of saxophones & to a lesser extent all the other woodwind instruments and one which causes problems that most players think is either their fault 'cos they're learners (we're all learners) or they're told that their chosen instrument has these inherent difficulties which all players must learn to overcome. Most saxophonists are brought up to believe it's harder to play the bottom notes - it isn't!! There are enough of those inherent difficulties without adding ones which are just mechanical faults of the instrument!!!

     Now as a repairer living in a world of subjectivism (music), I try to make what
I do as objective as possible but in order to illustrate why this regulation and airtightness is so important I'm going to go against that and anthropomorphise the instrument or tube!

     Try the following
     Take your Bb Clarinet or Saxophone and finger a C (Clart) or G (Sax). The process that's happening is this.

You've seen that note on the stave and your brain then tells you to form your embouchure in a certain way and put your fingers in that position. And it does this for every note on the page in very quick succession.

Now, just for fun lets turn that on its head and instead of thinking brain to instrument for each note, think instrument to brain. Artificially give your brain to the instrument so that when you finger half way down the tube to a Sax G or Clarinet C THE INSTRUMENT SAYS “I know what's wanted. It's an oscillation of the air down to that point in the tube”.

And if at the same time you press the octave or speaker key, IT says “Ah! I know what's happening now. There's a tiny hole up there at the top of the tube and he/she is using that to leak a bit of air out in order to break up the air stream, which will give them an upper G”. But if in addition to that deliberate leakage there's a tiny leakage from each of the keys above the G (that's about 13 of them by the way)! IT says “I don't really know what's wanted – I'm confused”. And of course in a fairly bad case that sort of leakage can prevent you from playing the bottom register at all (in the case of the saxophone) because the instrument thinks you've got the octave key down!! Put another way, for each note you require, and you're firing them out like machine gun bullets, IT'S got to make up its mind what's wanted – instantaneously – and it can't because it's being sent false messages about where you intend the tube to end!

     In musical instrument terms the nearest we can get to this mythical 100% seal is the oboe & piccolo and they get there because they can uniquely use a slight variation of the sealing system, but in fact all the smallest members of each instrument family suffer disproportionally more than the larger instruments & therefore need to seal better.

     Why is this?

     To start with, all the commonly used orchestral woodwind instruments, if the octave or whisper key is depressed, will sound an 8th or an octave above the lower note. To put it another way, if you play a concert A at 440 Hz and then press the octave key, the instrument will play the octave of that note i.e. A 880 Hz.

The clarinet however doesn't do that. When its speaker key is pressed (it's not an octave key any longer) the note jumps up a 12th or an octave and a half. This being the result of the shape of its bore & the way the air within is excited to form a sound wave and it seems on the face of it to be of little consequence, but it does have a significant effect on how the instrument reacts to air leakage.

     Leakage from all the octave instruments (saxophones, oboes, bassoons & flutes) manifests itself by it not being easy to play down to the lower notes, i.e. it gets harder and harder to play below say F or E. On the clarinet family which remember is an octave and a half instrument by nature, that same leakage doesn't really affect the bottom notes that much. The opposite situation occurs in that it's upper register production which is compromised, the worse the leakage the more difficulty in playing over the break and above.

     That's not the end of the story either. There's a further impact which has to be taken into consideration.

     We've already established :-

     Rule number (1) which is that there's no such thing as a 100% airtight instrument i.e. they all leak by some varying amount.

     Rule number (2) is that they all leak by a similar amount or amounts and for the same reason or reasons.

     It's quite hard to quantify the leakage other than 0%, which we've already established doesn't really exist, or 100% at the other end of the spectrum. Now given an instrument in otherwise perfect condition that has no cracks or faults in the bodywork, the only place where this leakage can occur is from these imperfect valves called keys and therefore the potential for that leakage is governed by the areas over which it's possible for it to escape. That effectively means the total circumferential length of all the tone holes on that tube. But hang on a minute, the tubes themselves are not the same. Some are larger and some smaller. So let's set them out in table form and see if can tell us anything.