Resonances have a noticeable effect on the timbre of musical sounds. For brass
instruments this is controlled by the length and shape of tubing, and how the
player constricts the lips.
For woodwind instruments, their tubular structures are resonators whose
resonant frequencies are controlled by opening or closing various holes.
The vocal tract has several resonances that emphasise various ranges of
frequency in the sound produced by the vibration of the vocal cords. By
changing the shape of the vocal tract, the frequencies of these resonances or
formants determine which vowel sound is produced.
The resonances of the soundboard of a violin greatly affect the timbre. The
suppression of some partials is important for the musical quality of the violin
tone.