among the musical instrument-makers, a kind of rule or scale whereby they adjust the pipes of their organs, and cut the holes of their hautboys, flutes, &c., in due proportion for performing the tones, semitones, and concords, just.

DIAPASON-Diax, in music, a kind of compound concord, whereof there are two sorts; the greater, which is in the proportion of 10:3; and the lesser, in that of 16:5.

DIAPASON Diaxente, in music, a compound concordance in a triple ratio, as 3:9. This interval, says Martianus Capella, consists of 9 tones and a semitone; 19 semitones, and 38 dieses. It is a symphony made when the voice proceeds from the first to the twelfth found.

DIAPASON Diatessaron, in music, a compound concord founded on the proportion of 8 to 3. To this interval Martianus Capella allows 8 tones and a semitone; 17 semitones, and 34 dieses. This is when the voice proceeds from its first to its eleventh found. The moderns would rather call it the eleventh.

DIAPASON Ditone, in music, a compound concord, whose terms are as 10:4, or as 5:2.

DIAPASON Semiditone, in music, a compound concord, whose terms are in the proportion of 12:5.