Mus. Obs. [f. TRIS- + DIAPASON, alter DISDIAPASON.] An interval of three octaves, a twenty-second; a note three octaves above or below a given note. (Cf. tridiapason, TRI- 4 a.)
1677. Plot, Oxfordsh., 293. And so will strike an under trisdiapason, or a 22d.
1706. Phillips (ed. Kersey), Tris-Diapason, or Triple-Diapason … a Chord, otherwise call’d a Triple Eighth.
