1. (n.) The octave, or interval which includes all the tones of the diatonic scale.

2. (n.) Concord, as of notes an octave apart; harmony.

3. (n.) The entire compass of tones.

4. (n.) A standard of pitch; a tuning fork; as, the French normal diapason.

5. (n.) One of certain stops in the organ, so called because they extend through the scale of the instrument. They are of several kinds, as open diapason, stopped diapason, double diapason, and the like.

English horn accord accordance air attune attunement bassoon baton block flute bombard bourdon carry cello chime chiming chromatic scale claribel clarinet clarion compass concentus concert concert flute concord concordance consecutive intervals consonance consonancy consort cornet cornopean cromorna cymbel degree descant diatessaron diatonic interval diatonic semitone dodecuple scale dulciana enharmonic diesis enharmonic interval enharmonic scale euphony fifth flute stop foundation stop fourniture fourth gamba gamut gedeckt gemshorn great scale half step halftone harmonic flute harmonics harmony heavy harmony homophony hybrid stop interval koppel flute larigot lay less semitone major scale measure melodia melodic interval melodic minor metronome minor scale mixture monochord monody music stand mutation stop mute nazard note oboe octave octave scale organ stop parallel octaves pentatonic scale piccolo pitch pipe plein jeu posaune principal quint quintaten radius range rank ranket reach reed stop register rhythmometer rohr flute scale scope second semitone sesquialtera seventh shawm sixth sonometer spectrum spitz flute step stick stop stopped diapason stopped flute strain stretch string diapason string stop sweep symphony synchronism synchronization temperament third three-part harmony tierce tone tone measurer tremolo trombone trumpet tune tuning tuning bar tuning fork tuning pipe twelfth unda maris unison unison interval unisonance vibrato viola voix celeste vox angelica vox humana warble whole step whole-tone scale