quality:corruption, structural:expansion
Embouchure and sound production

The bassoon embouchure is a very important aspect of producing a full, round, and rich sound on the instrument. The lips are both rolled over the teeth, often with the upper lip further along in an "overbite". The lips provide micromuscular pressure on the entire circumference of the reed, which grossly controls intonation and harmonic excitement, and thus must be constantly modulated with every change of note. How far along the reed the lips are placed affects both tone (with less reed in the mouth making the sound more edged or "reedy", and more reed making it smooth and less projectile) and the way the reed will respond to pressure.

The musculature employed in a bassoon embouchure is primarily around the lips, which pressure the reed into the shapes needed for the desired sound. The jaw is raised or lowered to adjust the oral cavity for better reed control, but the jaw muscles are used much less for upward vertical pressure than in single reeds, only being substantially employed in the very high register. However, double reed students often "bite" the reed with these muscles because the control and tone of the labial and other muscles is still developing, but this generally makes the sound sharp and "choked" as it contracts the aperture of the reed and stifles the vibration of its blades.

Apart from the embouchure proper, students must also develop substantial muscle tone and control in the diaphragm, throat, neck and upper chest, which are all employed to increase and direct air pressure. Air pressure is a very important aspect of the tone, intonation and projection of double reed instruments, affecting these qualities as much, or more than the embouchure does.

Attacking a note on the bassoon with imprecise amounts of muscle or air pressure for the desired pitch will result in poor intonation, cracking or multiphonics, accidentally producing the incorrect partial, or the reed not speaking at all. These problems are compounded by the individual qualities of reeds, which are categorically inconsistent in behaviour for inherent and exherent reasons.

The muscle requirements and variability of reeds mean it takes some time for bassoonists (and oboists) to develop an embouchure that exhibits consistent control across all reeds, dynamics and playing environments.