/ Dictionary / Index T tone cluster: Meaning and Definition of Find definitions for: tone' clus"ter Pronunciation: [key] — Music. Music. a group of adjacent notes played on a keyboard instrument typically with the fist, forearm, or elbow, similar groupings also occurring in orchestral music. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. tone arm tone color Related Content Daily Word Quiz: secular Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language