The effect of overblowing clarinet impedance peaks on sound production, playability, and intonation

Playability and quality of tone production on a clarinet with an applied fingering may be described, at least in part, by its corresponding acoustic impedance, a physical property of the instrument that may be measured in isolation of the player. Impedance curves, the magnitude of the acoustic impedance at measured frequencies, illustrate the acoustic response of the instrument, with a peak at a particular frequency implying a favorable spectral region for sound production. Clarinet impedance curve measurements, taken of various standard and extended fingerings and configurations, are viewed alongside the spectral magnitude of several corresponding sound examples, played by the author using advanced techniques regularly employed in her performance practice. When overblowing higher impedance peaks, the intonation of the produced sound is normally below the peak frequency. Since the player is usually striving to play the pitch associated with a particular fingering, it is less common to explore the extent to which the sounding frequency can be made to go above the target and toward the impedance peak frequency. In this context, it is discussed how sound production and playability, defined by tonal stability, intonation, and spectral quality, are affected when overblowing several fingerings of the full and partial clarinet.