Acoustics of baroque, classical and modern flutes

baroque flute


Music Acoustics UNSW

modern B modern C classical C classical D classical flared baroque B3
D4 D#4 and Eb4 E4 F4 F#4 G4 G#4 and Ab4 A4 A#4 and Bb4 B4
C5 C#5 D5 D#5 and Eb5 E5 F5 F#5 G5 G#5 and Ab5 A5 A#5 and Bb5 B5
C6 C#6 D6 D#6 and Eb6 E6 F6 F#6 G6 no G#6 on baroque flute A6


Acoustic and Fingering Schematic
a covered tone hole or key pressed
an uncovered tone hole or key not pressed
a partly covered hole

Details in fingering legend.

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

Impedance spectrum of a baroque flute measured at the embouchure hole using fingering for B4 and B5. Z is plotted in dB, i.e. 20 log(Z/Pa.s.m-3).

From E4 to B4 and E5 to B5, the simple fingerings (i.e. those that do not involve cross fingering) serve for two notes. The flutist uses the same fingering for B4 and B5, but changes the speed, length and shape of the jet. The absence of cross fingerings allows the second minimum to be harmonic (hence two strong harmonics in the sound spectrum).

The series of open holes acts as a filter to pass high frequencies (the wave doesn't reflect as well for high frequencies, so the instrument doesn't resonate as well). For this flute, the effect occurs not far beyond 1 kHz (it depends on the size of the holes). This effect diminishes the size and regularity of minima (and maxima), and so reduces the power at high frequencies. On the classical flute, the effect appears at around 1.5 kHz, and it is above 2 kHz on the modern flute. Hence only two minima are harmonic and so only two harmonics in the sound spectrum are strong. These suffice, however, to give a brighter timbre than that of the cross fingered notes nearby.


Sound spectrum of a baroque flute played using fingering for B4.

Sound Clip

You can hear B4 played by Matthew Ridley.

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.