frequencies and amplitudes. This is called a Fourier series, Fourier
decomposition, or Fourier analysis, named after the French mathema-
tician Joseph Fourier (1768-1830), who studied this phenomenon two
hundred years ago. It is a beautiful mathematical property of vibra-
tion. For sounds produced by musical instruments, the components
of the Fourier series are associated with the specific vibratory modes
of the strings and air cavities of the instruments.
Figure 15.7. Jew’s harp, khomus, scacciapensieri.