Acoustics of the clarinet

Bb clarinet

C#7

Music Acoustics UNSW

index
E3 F3 F#3 G3 G#3 A3 A#3 B3
C4 C#4 D4 D#4 E4 F4 F#4 G4 G#4 A4 A#4 B4
C5 C#5 D5 D#5 E5 F5 F#5 G5 G#5 A5 A#5 B5
C6 C#6 D6 D#6 E6 F6 F#6 G6 G#6 A6 A#6 B6
C7 C#7

Impedance

Fingering
a key depressed
a key not depressed
a hole covered
a hole uncovered
a part of the mechanism that is not normally touched
Details in fingering legend.

Acoustic schematic
a closed tone hole
an open tone hole

Non-specialist introduction to acoustic impedance
Non-specialist introduction to clarinet acoustics

Notes are the written pitch.
Frequencies are the sounding frequency, for Bb clarinet.
Unless otherwise stated, the impedance spectrum is for a Bb clarinet.


Impedance spectrum of a Bb clarinet measured using fingering for C#7.

At high frequency, things get very complicated. High frequency waves can travel further past open tone holes (the air in the tone hole doesn't have much time to move at high frequencies) and so the pitch of the high frequency peaks are thus affected more than the low frequencies by the subtle effect of reflections near the open tone holes at the end of the bore. Yes, we could think of this as a somewhat flat seventh harmonic of E4. Or a very sharp ninth harmonic of A#3. For notes so far above the cut-off frequency, the entire bore is involved and one could say that any open tone holes operate not only as register holes, but as minor adjustments to the frequency of the desired resonance. No problem for Catherine, however. She just plays it (sound spectrum and file below).

Sound


Sound spectrum of a Bb clarinet played using fingering for C#7.
For more explanation, see Introduction to clarinet acoustics

Sound Clip

You can hear C#7 played.


Fingering legend
How were these results obtained?

Contact: Joe Wolfe / J.Wolfe@unsw.edu.au
phone 61-2-9385-4954 (UT +10, +11 Oct-Mar)
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