Octave

(Eng., Fr.; from Lat. octava, eighth; It. ottava; Ger. Oktave). 1. A series of eight consecutive DIATONIC tones.2. The INTERVAL. Different octaves bear special names, more or less acceptable in international nomenclature (see SCALE(S)). The earliest type of POLYPHONIC singing was at the interval of an octave, with boys singing an octave higher than men.

Concealed, covered, or hidden octaves (or fifths), PARALLEL octaves (or fifths) suggested by the progression of two parts in similar motion to the interval of an octave (or fifth); parallel octave, CONSECUTIVE OCTAVES; rule of the octave, a series of HARMONIES written over the DIATONIC scale as a bass; short octave, the lowest octave of some old ORGAN MANUALS, in which some keys (and pipes) are omitted.

A curious explanation as to why the octave is the most perfect interval is given in an anonymous medieval music treatise. According to this writer, it was because octavo die Abraham circumcisus erat (because it was "on the 8th day that Abraham was circumcised").

3. In the organ, a stop whose pipes sound tones an octave higher than the keys touched, e.g., the PRINCIPAL. Also octave coupler, one uniting the 8 ' tones of one keyboard with those an octave higher on another; octave flute, 1. The piccolo. 2. An organ stop of 4' pitch; octave sign,

see OTTAVA; , see .