Kathleen Schlesinger, 1911 Encyclopædia Britannica, Volume 11… (1911)
“ The most valuable characteristic of the free reed is its power of producing all the delicate gradations of tone between forte and piano by virtue of a law of acoustics governing the vibration of free reeds, whereby increased pressure of wind produces a proportional increase in the volume of tone. The pitch of any sound depends upon the frequency of the sound-waves, that is, the number per second which reach the ear ”
