/ Dictionary / Index D diapason normal pitch: Meaning and Definition of Find definitions for: diapa'son nor'mal pitch' Pronunciation: [key] — Music. Music. a standard of pitch in which A above middle C is established at 435 vibrations per second. Also called Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. diapason diapause Related Content Daily Word Quiz: spectral Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language