On a bright, clear afternoon in Hollywood, Philip Glass is considering why it might be that, aged 80, he has outlasted his younger friends and collaborators, David Bowie and Lou Reed. He traces it back to the excesses of the Seventies, an era whose hedonism he deliberately observed from the sidelines.
“I didn’t have the money to corrode my body as some of my friends did,” he says wryly. “When I was a young man I was afraid of that lifestyle and I stayed away from it. I hate to put it so crudely, but I gained an extra 20 years of life.”