Harmonic timbre

A timbre is harmonic when its frequency spectrum has the property that all non-negligible frequencies are multiples of the lowest frequency (as is the case with most methods of sound production, including the human voice, most instruments, and square/saw/triangle waves). This causes the sound wave to be periodic (where the frequency of the sound wave is the frequency of the lowest note in the spectrum) and causes just intervals to be concordant.

If a timbre is not harmonic, it is inharmonic.