Sound is due to the vibrations of a source, such as a mus.
But other factors enter into the control of pitch. The varying quality of the sound produced by different instr. Almost all vibrations are compound, e.g. a sounding vn. str. These notes are not easily identifiable by the ear but are nevertheless present as factors in the tonal ens. The numbers attached to the harmonics represent also the ratios of the frequencies of the various harmonics to the fundamental.