(music) A musical interval of the Western twelve-semitone system consisting of thirteen semitones and spanning eight degrees of the diatonic scale. It is one semitone wider than a perfect octave and enharmonically equivalent to a minor ninth/compound minor second.

plural of contra-octave

plural of perfect octave

plural of octave flute

A flute that is smaller than a Western concert flute and pitched nearly an octave higher. / A flute stop in an organ pitched an octave higher than the standard pitch.

(music) The octave that begins on the C that is two ledger lines below the staff of the bass clef

(music) The octave directly below the great octave.

plural of great octave

plural of pseudo-octave

(music) An interval whose frequency ratio is not 2:1 (that of the octave), but is perceived or treated as equivalent to this ratio, and whose pitches are considered equivalent to each other as with octave equivalency.