Text: An augmented fourth, containing three whole tones. The use of the tritone was anciently forbidden in harmony or counterpoint, as it was regarded in the light of what is called a false relation. It was not permitted to be employed in the upper note of one chord and the lower note of the following. In each case it was called mi contra fa, the leading or sensitive note being known as mi, and according to the old rules, mi contra fa diabolus est.

See Also: FALSE RELATION; INTERVAL

Source: 125