Pushing in and pulling out

July 17, 2015

As a follow-up to last month’s post on playing in tune, I would like to revisit the idea of adjusting woodwind tuning mechanisms (generally by the “pushing in” or “pulling out” of some joint of the instrument). Note that this information is probably of most value to advanced players; beginning and intermediate players should be focusing their intonation efforts on breath support and voicing.

A simplistic view of “tuning” is that “pulling out” makes the instrument play a little flatter and “pushing in” makes it play a little sharper. The problem is that not all notes are affected equally.

For example, let’s keep the math simple and imagine an instrument that is 100cm long with its tuning mechanism pushed all the way in. And let’s imagine that instrument has a tonehole that can be opened to give the tube an effective length of 50cm.

tuning_percent_before

Now suppose that you pull the tuning mechanism out by 1cm. The lengths of the tube for the notes are now 101cm and 51cm.

tuning_percent_after

They have changed by the same absolute length, but not by the same percentage. The shorter-tube notes (those with more open toneholes) are more dramatically affected by changes in the tuning mechanism than the long-tube notes are.

This is a problem without a tidy solution. A high-quality instrument is built to play at a specific pitch standard (A=440, A=442, etc.) with the tuning mechanism adjusted to a precise location and at a specific temperature. The “easiest” way to play in tune is to own an instrument built to your preferred pitch standard (such as the one your ensemble tunes to), play only in spaces having a suitable temperature, and adjust the tuning mechanism to that precise spot every time. In reality, of course, we need the flexibility of a moveable tuning mechanism to adapt to a variety of circumstances, but we have to be aware of the consequences of pushing in and pulling out.

An additional wrinkle, so to speak, is that adjusting tuning mechanisms can introduce perturbations to the instrument’s bore. Skilled instrument makers can purposefully create perturbations to improve an instrument’s intonation, but undesirable perturbations can have non-intuitive effects on the instrument’s scale.

Here’s what I mean by the tuning mechanism creating a perturbation. Notice how when the tuning mechanism is pushed in the bore is a consistent width, but when the tuning mechanism is pulled out, there is a wider spot in the bore:

perturbation

This is one of the benefits of tuning a clarinet or bassoon flatter by switching to a longer barrel or bocal: you get the additional length you need without creating a bore perturbation (though remember, notes are still affected unequally). A workaround for clarinetists is to use tuning rings, preferably matched to the instrument’s bore size at that joint, to fill in the perturbation.

Most of getting tuned up has to do with obtaining a high-quality instrument and playing it with high-quality basic technique (good breath support, voicing, and embouchure). That last little bit of improvement is complex and elusive, and understanding some of the reasons for that can help you get there.

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