New York composer David Lang talks punch-ups and prepared pianos.

It was 25 years ago that David Lang, then a young American composer and founding member of the fledgling ensemble Bang On A Can, “had a big fight” with his hero John Cage. “It was at our first festival,” he recalls. “We invited him to the concert and we had no idea if he was coming or not. He showed up extremely early because we had programmed his piece at 1am and he said that it was past his bedtime.

“My job at the early Bang On A Can festivals was taking the tickets at the door. I got into a fight with John Cage because I refused to let him pay. He said he wanted to support us and I said ‘absolutely not’, so there was this gigantic standoff at the doorway. He stayed at the first festival for 4 hours, and he really loved it. We felt we were on the same page as him and had the same openness to the world.”

That openness led the Manhattan-based group to program at least one piece by John Cage – some of them world premieres – every year until...