How did you and Philip Glass first meet?

It was in 1964 in Paris. He was studying composition with Nadia Boulanger and had become friends with [sculptors] Richard Serra and Nancy Graves. I was on a Fulbright grant to Vienna, visiting Richard and Nancy, and that's when I met Phil. I didn't see him again until 1967 when we moved to New York and he was plumbing our lofts in SoHo. In 1968 I photographed Phil. That portrait started a four-decades-long period of recycling and has produced more than 100 different works in all kinds of mediums.

What is it about that first picture that continues to speak to you?

I love the way he looks, with heavy, hooded, druggy eyes and a very sensuous mouth. And his Medusa-like hair is great for formal invention because it lends itself so well to fingerprints or dots. It's not that I was cashing in on anyone's notoriety: we were both unknown at the time. I wanted everyday people, not superstars, because that's what Andy [Warhol] was doing.

Of course many people you portrayed became famous later.

Phil used to say anybody who showed up [in my studio] had an instant career leap. It did seem that way. Bob Israel for instance, the set designer for the original production of Satyagraha, was at that same shoot that day in 1968, and I painted him the next year, but he and Phil didn't really meet or collaborate for another ten or 15 years. They could have talked to each other right then and there and started working together!

Do you see a correlation between Phil's music and your art?

Absolutely. All of us who were trying to figure out how to make art in the late sixties wanted to make works that didn't look like anybody else's. There was a tremendous desire to find some way of working that would push us someplace else. We were all nurtured in the same primordial ooze, and then we crawled ashore and all went in our separate directions. What informed us was the belief that following a process would set you free, that the use of extreme self-imposed limitations would guarantee your work could change and that you wouldn't keep doing the same thing over and over. Lightning struck in various disciplines at the same time because all these things were in the air.

Do you think you will go back to Phil's portrait at some point?

I always say I'm going to retire that photograph and haul it up into the rafters of my studio, the way they retire a basketball jersey. But every time I think I've wrung every bit of information out of it, along comes another medium, another opportunity to take another look at it. Phil recently returned the favor and composed A Musical Portrait of Chuck Close.

And can you see yourself in it?

You know, unless you have music that attempts to sound like rain or something like that, it's not likely that visual images come to mind. But the first movement is more like my earliest work, much more minimal and reductive, almost black and white. And the second is the musical equivalent of a riot of color. It's celebratory in much the same way I try to build these big color images out of lots of little pieces.

Why do you think Phil was drawn to Gandhi as a subject?

He's a believer in Tibetan Buddhism. Many artists are interested in that world: it's really a kind of counterculture belief in alternative religions, which I think probably comes from that same desire to throw whatever religion you were raised with out the window. If you think about 1968 as the time when most of us were sprung on the art world: it was a time of tremendous revolutionary change. The war and the Democratic convention and Bobby Kennedy and Martin Luther King's death following the assassinations of John F. Kennedy and Malcolm X... But I think that when Phil chooses a subject, he still peoples the work with his friends and colleagues. The subject matter might be Einstein or Gandhi, but it's still built on his friends and the members of his ensemble.

How does Phil feel about your many portraits of him?

I'm sure it's annoying as hell! The number of people who have come to him and said, "Philip Glass, I love your painting..." But I suppose it's one of those things where the positive aspects of a relationship outweigh the annoyance factor. For me, it's an immense pleasure to be involved with someone's work over an extended period of time, and to watch the changes and permutations and the growth and development. It's a fun ride to watch Phil.

CHUCK CLOSE PHILIP GLASS 40 YEARS opens March 17 in Gallery Met and runs through the end of the current Met season.