It's late on a Sunday night and Philip Glass is tired. It's obvious from the way he digs at his eye sockets with thumb and forefinger and pushes a hand through his crop of curly hair. He lapses into an opaque gaze that freezes his eye movement and focuses on nothing. For a moment, he is silent. Then his face comes alive and in his conversation — or, more accurately, his lecture — Glass is animated and exuberant again, filled with energy as he meanders without transition from topic to topic, rarely staying on message.

On this night, Glass teamed with renowned Mandingo griot (a person trained from childhood to memorize, perform and perpetuate the music of his culture), Foday Musa Suso, for a concert of Euro-African classical works under the title "The Screens," a collection of collaborations by Glass and Suso based on a play by the controversial French writer Jean Genet. Only ten minutes earlier, Glass guided his four-man ensemble toward a faded out conclusion of its encore piece at the Calvin Theatre in Northampton, Massachusetts. A second standing ovation ensued in the audience and the musicians walked off stage to cheers of "More, more." Now, changed and waiting backstage for the crew to strike set and pack for the ride back to New York, Glass' enthusiasm for talking music contradicts the fatigue set in the circles under his eyes. He rubs his eyes again, then continues.

"It's a most interesting time," he says, helping himself to backstage, post-concert fruit and cheese and crackers. "On the one hand, it's a horrible time to be alive. On the other hand, it's the very best time to be alive. On a social level, it's a complete disaster, of course. But the funny thing is, there's never been a time when an individual had more available to him in terms of history, culture, a kind of global view of humanity, civilization. From the point of view of the individual, the opportunities of understanding transformation have never been better."

Labeled one of the four founders of compositional "minimalism" in the 1960s, Glass has since left behind the despised moniker by producing a succession of monolithic harmonic constructions and elaborate music-theater works. And while he has slowly come to be respected in the stuffy circles of "legitimate" classical music, he continues to contribute to what his critics would call popular art. Though his fame has become international, Glass has had to consistently evolve in the creation of his art and career strategy. In the process, he has confounded some of his critics, won over others, and gave some of his harshest detractors plenty to write about.

Never mind about them, Glass says of those who criticize him for his choices to work across cultural gaps. "I've been taken to task by different writers," he says. "But I don't pay much attention to it. I don't worry about it very much. I've learned that the culture of writing about music and the culture of listening to music aren't the same. What Verdi used to say about his music: he said, 'No one likes it but the public.'"