Quarter-tone (Fr. quart de ton; Ger. Viertelton; It. quarto di tono)
- Julian Rushton
(Fr. quart de tonGer. VierteltonIt. quarto di tono)
An interval half the size of a semitone. The term was used by some 17th- and 18th-century theorists to denote the distance between a sharp and enharmonically distinct flat in mean-tone temperaments (e.g. D♯–E♭). In most contexts, however, it refers to an interval of of an octave, or 50 cents.
Quarter-tones form part of the enharmonic genus of ancient Greek music theory (see Greece §I, and Diesis); they have also been discussed in the context of medieval plainsong (see Gmelch), and were considered by Hothby in the late 15th century (see Reaney) and by Coprario in the early 17th (see Field). Interest in them increased steadily during the 19th and 20th centuries. The ‘Aphorismen’ of Heinrich Richter, published in 1823 under the pseudonym ‘Amadeus Autodidactos’, ventured to propogate quarter-tone music, and Johanna Kinkel urged the emancipation of the interval in her essay of 1853. The Russian futurist painter Mikhail Matyushin (...