Why Does A Mouthpiece shut down ?


Why does a mouthpiece shut down? The causes are known and they are fixable.

An amateur player wants to know why his highly regarded alto mouthpiece just “shuts down” suddenly while he is playing. The responses, all well intentioned, are a collection of “the usual suspects”:

  • ‘You must take more mouthpiece”
  • “You need a bigger tip opening”
  • “Practice”

There is one response that gets closer to reality. It suggests that the issue may be connected to a certain facing length.

Now, “taking more mouthpiece” may relieve the problem, but that is, in fact, a workaround. It masks the problem, almost certainly. “Take more mouthpiece” almost always screams “workaround”.

“Bigger tip”? Well, that’s another workaround, and it works because it brings a completely new facing into the equation. It is just as easy, and more honest,  to say “spend another $300 and see how that works for you”.

“Practice” is the worst of the responses, as it says “the problem is you”. Maybe ( one in 500) , but likely not actually true.


So, why DOES a mouthpiece suddenly ‘shut down”?

It most often has to do with one or both of two things: the facing and/or the reed itself.

But, it isn’t exactly the facing “length”. Rather it is the facing “curve” and, actually, it is the facing curve at one or more specific spots along the curve.

The other culprit, so to speak, is the reed itself. If the reed is pliable and bends easily ( soft or light ), it will have a hard time on a poor facing curve for a lot of players, beginners or not.

The problem can be eliminated by, again, one or both of these changes (often both for a student):

  • A corrected facing curve
  • Perhaps a little firmer reed choice.

So, what is actually happening?

The reed is bending and contacting the facing curve, which effectively stops it from vibrating. Experienced players can feel this start and avoid it, but students have not yet developed that touch, nor should they need to do so at this time. For experienced players, this might happen if a reed is or becomes too flexible.

If enough of the reed contacts enough of the curve: shutdown.

A firmer reed bends less but can present a student with all kinds of other problems. And the facing curve remains wrong and a problem waiting to pounce.

The other aspect to this issue of “shutting down” is an acoustical one, as the sound wave exerts a force on the underside of the reed, so certain notes themselves can be involved as well.


But it is almost always the facing curve and the reed itself.

Fix the curve and life is good.

Often, the student contributes to this by exerting too much pressure on the reed (hence the “take more piece” advice). But, while learning to enjoy and play the horn, there is no need to deal with the equipment side of this issue by making a gross adjustment that would be unneeded if the piece was correct to begin with. And, as experienced players, we know that the tone is immediately affected to some degree when “more piece” is taken. Intonation can also become unstable at first, thus creating another issue. That is, unfortunately, the legacy of “workarounds” all too often.

My point boils down to this: if you put a Chevy fuel injector on an Alfa Romeo, there will be problems. Telling somebody to get creative with the gas pedal isn’t particularly helpful. Get an injector that works properly on that 164, and have fun.