An unusual Piano Concerto by the American composer Lou Harrison had its premiere performance in New York on this day in 1985. The famous jazz pianist Keith Jarrett, for whom it was written, was the soloist.

Now, Lou Harrison’s music was often marked by its eclectic blending of East and West, and on occasion, Harrison employed non-Western or unusual instruments in his scores, including his own home-made Javanese-style gamelan constructed from old brake drums and clay flowerpots. But that wasn’t what made his Piano Concerto so singular.

“I’ve always wanted to write a piano concerto which utilizes two or three pianos on stage, each tuned differently,” said Harrison. “And Keith was willing to try that. But in the end, I decided to use one piano in a tuning I really enjoy.”

In Harrison’s concerto, the piano is not tuned to the “equal temperament” system in use in Western music since Bach’s day. The black keys are tuned to the medieval system of mathematically exact intervals of 4ths and 5ths, while the white keys reproduce the “just intonation” system common in the Renaissance and Baroque.

And so the familiar instrument has an unfamiliar ring, but one that Keith Jarret loved: “At times in the piece,” he said, “whole chords sound like bells.”