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Re: High Pitch Instruments

Author: Chris P
Date: 2011-02-24 05:13

Mike, on guitars if you shorten the strings from the fingerboard end with a capo (as opposed to the bridge end where the strings are fixed), then the ratio between string length and the distance between the frets will be preserved, so this will work and keep everything in tune with itself. So of you stop the string with a capo at the first fret making E an F, then the midpoint of the string will now have moved up so the 8ve F will now be at the 13th fret - and E will still be at the 12th fret but this is no longer the midpoint of the string (you can check this against the natural harmonics) as the length has been shortened.

In woodwind terms you'll notice if you hold an oboe and cor next to each other and line them up so the oboe's low C tonehole lines up with the cor's mid G tonehole, you'll see the toneholes on each instrument roughly line up with each other. Take an A and Bb clarinet and place them next to each other so the lowest tonehole on the Bb lines up with the second lowest tonehole on the A and you'll see the remaining toneholes roughly line up as the length of tubing to make the identical sounding note will be the same length on both instruments.

So shortening or lengthening things at the far end of woodwinds won't affect the scale as they're lengthened or shortened by the correct amount and won't have any detrimental effect on the intonation of the rest of the instrument. It's the lengthening at the top end without being able to relocate toneholes in relation to the distance from the reed/mouthpiece/embouchure hole that will throw an instrument out.

Clarinets are in tune with themselves with a specific length barrel - usually 67mm - but using a shorter barrel will have more effect on the upper part of the instrument than the lower notes. Saxes are in tune with themselves when the mouthpiece is at a specific position and moving it back and forth only has a minimal effect ont he overall tuning, again more effect on the LH and high notes than the lower notes instead of uniformly raising or lowering the overall pitch.

But with shorter barrels and mouthpiece position we do compensate for the intonation as we go. A clarinet or sax player who plays very flat won't have the problem cured by using a short barrel or pushing the mouthpiece on so there's no cork showing as this only raises the pitch of the upper notes - the problem is more to do with the type of mouthpiece used, the player's embouchure or a combination of both.

As an extreme example, if you put a tenor crook on an alto (if that's possible), then you'll throw the scale out completely as the crook is too long in relation to where the toneholes are set out. But if you remove a tenor's bell, the remainder of the instrument will still play perfectly in tune as it can be, but you'll lose the lower notes below E. Same with a flute if you remove the footjoint - the remainder will still play in tune as the scale is unaffected.

This is much easier for me to demonstrate than to write about, so I hope you've managed to follow what I mean.

Former oboe finisher
Howarth of London
1998 - 2010
The opinions I express are my own.

Post Edited (2011-02-24 06:57)

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