diap

Abbr. of diapason. _ diapa’son, Gr. pron., in E. (di-d-pa’son; in F., dé-dp-d-sén). 1. An octave. ‘d. (cum) diapente. An octave ' with the fifth—a twelfth. d. con diate eron. An. octave with the fourth—an eleventh. 2. Range. 3. Absolute pitch, as d. normal, international pitch, vide a (tr). 4. In the organ, the sonorous chief foundation-stops, one of 8 and one of 16-foot pitch on the manual, on the pedal, 16-foot; the open d. has metal pipes open at the top, the stopped d. has wooden pipes closed at the top. In other countries they are called principal.