Yo-Yo Ma began playing the cello at the age of 4. Now 57, he has received numerous Grammy Awards, the National Medal of Arts and the Presidential Medal of Freedom. In 1998 Mr. Ma founded the Silk Road Project, a nonprofit organization that brings together musicians from around the world. Last month, Sony Masterworks released his Silk Road Ensemble’s “Playlist Without Borders” CD and “Live From Tanglewood” concert DVD. Mr. Ma recently called from his home in Cambridge, Mass. A condensed and edited version of our conversation follows:

Do you ever wonder why it was you and not someone else who became a great cellist? What sets you apart?

Let me just say that I have no idea. I’m an accident. I don’t think there’s a rhyme or reason and I have spent a lot of time thinking about it. Why do I get these chances? Is it because I play faster? No. It’s a whole series of circumstances — some I work for, some come from my parents, my teachers, the points that are catalytic, the move, going to college, meeting my wife and knowing my children. It’s a confluence.

Earlier this year at the Aspen Ideas Festival you said it wasn’t until you turned 49 that you thought being a musician was cool. What did you mean by that?

Since I always played, as far as I can remember, I never said, “This is what I want to do.” And I think I always wondered: “Gee, could I have been this? Could I have done that? What would have happened if …?” What came up at age 49 is I realized that of all the things I’m interested in, the thing I’m most interested in is figuring out what makes people tick, why people think the way they do, why they act the way they do. And I realized that music is such a great way to investigate why people do what they do.