How do clarinet players do that big glissando in Rhapsody in Blue?
Several effects are used by the player to achieve this spectacular, smooth ascent in pitch. First, the clarinet has seven holes that are covered by the fingers, rather than keys. By gradually sliding the finger off the hole, one can obtain a smooth transition from one note to the next. This is how the first part of the glissando is achieved. The player can also change the position and force of the lower lip on the reed, thereby changing its natural frequency. Most importantly, however, s/he also uses the resonances in the vocal tract. Normally, the resonances of the instrument are so strong (have such high acoustic impedance) compared with those of the vocal tract that the latter make only modest changes to the pitch. However, in the upper range of the instrument the player can produce resonances of the vocal tract that can be comparable in strength with those of the instrument, so the note played tends to follow that of the tract resonances, which the player increases smoothly–with s
