These exercises are intended to promote smooth air-flow and efficient embouchure and slide movement.
When you play a pitch on a brass instrument, you are buzzing that pitch into your mouthpiece, i.e., you are making that pitch with your embouchure. The place where the air goes through your lips is called the aperture (French for ‘opening’) and this is where the buck stops…embouchure control is all about aperture control.
Your aperture changes slightly to make each pitch, which means that the muscles involved somehow change or move. Somehow, in some teaching circles, the idea that the aperture shouldn’t change when changing pitch has been taught. Most people now disagree with this concept and acknowlege that the aperture has to change in order to change pitch. Go ahead and try it. If you can change pitch without changing your aperture, let me know! 1 octave? 2 octaves? I don’t think I’m going to get any emails proving me wrong on this one! (the bigger your mouthpiece and the lower you buzz, the more obvious this movement becomes)
But too much change (movement) of the aperture gets negative results, and too little movement doesn’t work so well either…the necessary amount is what we are striving for. Embouchure movement should be as little and graceful as possible – but enough to get the job done. Watch in a mirror as you play.
Let the aperture move with the pitches but don’t overdo it – or underdo it! Try to keep the movement contained within the mouthpiece rather than extending beyond the rim.
On the trombone, one method of achieving and recognizing this minimal embouchure movement is to notice the feeling as you glissando from Bb to F (in 6th position) and back to Bb. Here’s a great time to watch in a mirror. The embouchure moves very little – this is our ultimate goal as we slur across partials too. Pay attention to the corners of the embouchure; they should be firm but not clenched. The sound should remain relaxed and resonant. If you hear the sound get twisted or feel – or see – something ungraceful happening, you’ll notice that they all are related. If you see something weird, you are going to hear something strange and feel something out of place. So notice one issue and it will steer you towards other issues that are related! The good news here is that if you fix the problem in one area then you generally have fixed all of the related issues too!
Play the first three notes of the exercise below. Practice this glissando until you feel comfortable. Then go ahead and play the whole line, alternating playing a glissando to F in 6th position with playing the F in 1st position.
Strive to use the same air and embouchure movement both during the glissando and the slur. This may not be possible, but use this as an ideal goal while experimenting with your air and embouchure to move as efficiently as you can.