The cent is a logarithmic measure of a musical interval introduced by Alexander Ellis. It first appears in the appendix he added to his translation of Herman von Helmholtz's On the Sensation of Tone As a Physiological Basis for the Theory of Music. A cent is the logarithmic division of the equitempered semitone into 100 equal parts. It is therefore the 1200th root of 2, a ratio approximately equal to (1:1.0005777895).
- Herman von Helmholtz (1912). On the Sensation of Tone As a Physiological Basis for the Theory of Music, Alexander Ellis translation. Longmans, Green.