Accidental chords

(Mus.) those which contain one or more tones foreign to their proper harmony.

See also: Accidental

Webster's Revised Unabridged Dictionary, published 1913 by G. & C. Merriam Co.
References in periodicals archive ?
After the war, Gus sang bass in the Accidental Chords for several years, along with Todd Lind, Ernest Holmlund, Angelo Solinas, and later, Paul Holmstrom.