overblowing

Overblowing is the manipulation of supplied air through a wind instrument that causes the sounded pitch to jump to a higher one without a fingering change or the operation of a slide. Overblowing may involve a change in the air pressure, in the point at which the air is directed, or in the resonance characteristics of the chamber formed by the mouth and throat of the player. (The latter is a feature of embouchure.)

In some instruments, overblowing involves the direct manipulation of the vibrating reed(s), and/or the pushing of a register key while otherwise leaving fingering unaltered. With the exception of harmonica overblowing, the pitch jump is from one vibratory mode of the reed or air column, e.g., its fundamental, to an overtone. Overblowing can be done deliberately in order to get a higher pitch, or inadvertently, resulting in the production of a note other than intended.