Harmonies

Don Heckman refers to “low overtone harmonies,” in his review of the Max Roach Quartet (Jazz Review, April 6).

Six musician friends offered two guesses (multiphonics, primary chords) and four I-don’t-knows. Two music dictionaries were no help either.

I give up. What are “low overtone harmonies”?

DAVID M. SHERR

Santa Monica

“Multiphonics” is a pretty good definition, says Heckman, who adds that to understand it , it helps to be a saxophone player.