Bass (music) (Ital. basso, low), in music, the lower or grave part of the musical system, as distinguished from the higher or acute (treble) part. Practically middle C marks the division. The term is also applied to the lowest or deepest male voices. In this sense there are four kinds: the baryton, the basso cantante, the basso profondo, and the exceptionally deep contra basso, said to be peculiar to Russia. The Double Bass, or contra bass, is the deepest toned of stringed instruments.