How players use their vocal tracts in advanced clarinet and saxophone performance

How and when is the player’s vocal tract important in clarinet and saxophone performance? In a simple model, the acoustical impedances of the instrument (a resonator downstream from the reed) and the player’s tract (an upstream resonator) appear in series and in their sum is in parallel with that of the reed. Using impedance heads built into functioning mouthpieces, we made measurements of the acoustical impedance spectrum inside the mouths of clarinettists and saxophonists as they played. Acoustic impedance spectra of the clarinet, soprano and tenor saxophone bores were also measured for all standard fingerings, and some others. From these, we calculate the series impedance, and add it in parallel with the inferred reed reactance. For fingerings high in the tenor saxophone’s second register, impedance peaks of the bore decrease rapidly with increasing pitch, making playing the altissimo range of this instrument more difficult than that of the clarinet, which has strong peaks into the fourth octave. Peak values on the saxophones fall below 30 MPa.s.m -3 above the first 2.7 octaves, ending the standard range available to amateurs. To play the altissimo notes, experts produced strong vocal tract resonances upstream with impedances 10-40 MPa.s.m -3 and tuned them so that the peak in the combined bore-tract-reed impedance corresponded to the desired note. While expert saxophonists adjust their vocal tracts thus for altissimo playing, inexperienced players do not and consequently cannot produce these notes. Similar vocal tract adjustments were observed for other advanced techniques such as bugling and multiphonic selection. When pitch bending in the second (clarino) register of the clarinet, experienced players produced strong tract resonances with impedances up to 60 MPa.s.m -3 , comparable in magnitude with those of the clarinet bore (40-50 MPa.s.m -3 ). Thus during pitch bending, the sounding pitch is controlled by smoothly varying a strong resonance in the player’s vocal tract. The phases of the bore, tract and reed impedances explain why pitch bending downwards is easier than upwards. In contrast, during normal playing on both the clarinet and saxophone, both amateur and experienced performers produced vocal tract impedance peaks with only moderate magnitude, and do not tune that resonance specifically to the note being played.