Unison [prime] (Fr. unisson; Ger. Prime; It. prima)
- Julian Rushton
[prime] (Fr. unisson; Ger. Prime; It. prima)
(1) Two or more notes sounding the identical pitch, usually though not necessarily at the same time. In a number system with semitone = 1, tone = 2, the unison ‘interval’ is equivalent to zero. It would be theoretically possible to call the interval C–C♯ an ‘augmented unison’ but in practice it is normally referred to simply as a chromatic semitone. Similarly, Enharmonic notation may produce unison between notes with different letter names (e.g. F♯ = G♭).
(2) The simultaneous execution of one polyphonic part by more than one performer or performing group (e.g. the first violin section of an orchestra), either at exactly the same pitch or at the interval of an octave, double octave etc. (see also Doubling); such execution is said to be ‘in unison’ and is often indicated in scores by the Italian all’unisono.
(3) ‘Rhythmic unison’ is an informal equivalent for a Homorhythmic...