Mario Davidovsky, a Pulitzer Prize-winning composer who opened up new vistas in chamber music by pairing live acoustic instruments with electronics, died on Friday at his home on the Upper West Side of Manhattan. He was 85.

The cause was heart failure , his son, Matias , said.

Like many of his fellow composers in the 1950s and ’60s, Mr. Davidovsky was drawn to the new possibilities offered by technology. But he was uneasy with the prospect of music that was immune to human interpretation.

Beginning in 1963 with “Synchronisms No. 1” for flute and tape, he coaxed electronic sounds into partnership with traditional instruments to create musical pas-de-deux that were full of mystery and drama. His “Synchronisms No. 6” for piano and electronic sounds won the Pulitzer Prize for music in 1971.

The composer Eric Chasalow , who studied with him beginning in 1977, said in a phone interview that Mr. Davidovsky was among the first “to make electronics nuanced the way a violin is,” adding, “He tried to make the electronic an extension of the organic.”