Acoustics of baroque, classical and modern flutes

modern flute
B foot


Music Acoustics UNSW

modern B modern C classical C classical D classical flared baroque B3 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 D7 D#7 E7 F7 F#7 multiphonics


a key depressed
a key not depressed
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 flute acoustics

Impedance spectrum of a modern flute with a B foot measured at the embouchure hole using fingering for D7. Z is plotted in dB, i.e. 20 log(Z/Pa.s.m-3).

Notes in the fourth octave are well above the cut-off frequency for the flute, so virtually the whole of the bore is involved in the standing wave. It is therefore inappropriate to give qualitative explanations of the impedance spectra in terms of simpler fingerings. Rather, any open holes are acting as register holes, and their exact placement affects the intonation and depth of the working minima.

Notice that all have some deep minima at low frequencies: these cause little inconvenience because the jet is fast for playing altissimo notes. The principal requirement for fourth octave fingerings is to have a minimum whose frequency is approximately correct, whose depth is as great as one can find, but not to have any other substantial minima at nearby frequencies. Note that, in the sound spectra, there are small, inaudible bumps at frequencies corresponding to the minima in the impedance spectrum.


Sound spectrum of a modern flute with a B foot played using fingering for D7.

Sound Clip

You can hear D7 played by Geoffrey Collins.

The Virtual Boehm Flute may suggest other fingerings for this note.
Fingering legend
How were these results obtained?
Acoustic measurements are available for these flutes -
modern B, modern C, classical C, classical D, classical flared, baroque
Sound clips are available for modern B, classical flared and baroque
To compare flutes, it is easiest to open a separate browser window for each instrument.

Copyright © Academic Press. JSV+ Joe Wolfe, John Smith, John Tann and Neville H. Fletcher, Acoustics of baroque, classical and modern flutes
Revised to include the baroque flute 2001.