Mickey Hart is best known as a drummer for The Grateful Dead, or what he has called “an extraordinary expedition into the soul and spirit of music, disguised as a rock and roll band.” But even before the death of the band's lead guitarist, Jerry Garcia, in 1996, Hart had branched out from the Dead's psychedelic folk and blues, growing increasingly interested in rhythms from around the world.

Working with the Library of Congress Endangered Music Project, Hart has led an effort to record endangered music from cultures facing extinction. In 1991, his album "Planet Drum," on which he played with Sikiru Adepoju, Flora Purim, Giovanni Hidalgo, and others, received the first Grammy offered for Best World Music.

For Hart, however, drumming isn't found only at the ends of the earth. Rhythms, as he explains in this interview, flow deep within our bodies and not only promise self-revelation spiritually but integrate our physical selves. He has pioneered the exploration of the effect of rhythm on afflictions associated with aging, co-founding the Rhythm for Life Foundation.

For those of us raised on rock, drumming means a barrage of noise, a celebration of overstatement. But his recent CD, which Hart describes as "influenced by the spirits of the forest," has a gentle, unforced beauty and an authenticity that is emblematic of Hart's own understated presence.

Hart's quietness, however, belies his authority in matters spiritual and musical. He has written three important books that explore the interplay between rhythm and spirit: "Planet Drum," "Drumming at the Edge of Magic," and most recently, with Fredric Lieberman, “Spirit Into Sound: The Magic of Music," for which the CD is the musical complement.

Could you start by explaining the title to your CD “Spirit Into Sound”? "Spirit" sounds more like a verb than a noun, a process...
"Spirit into sound" means giving form to spirit, which is unseeable. But through music, and rhythm, I give it form.

So rhythm is already in existence, waiting for us to uncover it?
Rhythm is the essence of who we are. Our bodies have rhythms, the world has rhythms, and culture has rhythms. Where they come into contact, there can be chaos, or, if things are aligned, they can be harmony. But everyone has rhythms, I mean, your pulse and your heart. Your heart is not just for pumping blood. It has rhythm and content.

And everybody's rhythm is different?
Everybody. It's like your fingerprint. No two hearts beat exactly alike. So drumming means connecting with your own rhythm, your own DNA, your own print. If you don’t have a connection with your rhythm, you can't give it to anyone else. If you can’t make that connection, you’re just beating stuff up.

On "Spirit Into Sound," you must play more than 20 different drums. How do you learn to play a new drum?
I take it into my house with me. If it is small enough, it comes into the bedroom, and I play it a little each day and get to know it.

Do you have any rituals that you use when you play?
I use visualization a lot. I'll concentrate or stare at something, I'll look at a tree or just a focal point and think of a rhythm. Or I’ll mumble a rhythm, a mantra, or a sound or something even that is inaudible.

Or I see patterns. I see my fingers moving on a membrane, like drumsticks moving, and I try to connect them to the sound, sort of like connect-the-dots. That's good if you’re in an airport and can’t make sound, or, you know, if you’re in a hotel room late at night.

In many ways, it's like yoga. It’s a rhythm. You breathe in and out, you get into the rhythm. Then all of a sudden, you find a certain center of gravity, a certain calmness. It’s a power--that’s what you are after, you're after inner power.

So you do yoga?
Breathing and yoga, both of which are rhythm exercises. That’s how I connect to my soul. The soul doesn’t have a P.O. box, you know. So you have to look for it every day anew. It’s never in the same place. That's why you can never repeat a ritual exactly, because then you're just punching a clock. That won’t work, or works a few times and then you become numb.

You seem to know a lot about different religious traditions. Which tradition is closest to what you follow?
I trust the Hindu belief, Nada Brahma: God is sound. The universe started in a vibration, and that first sound is still washing over us. That's the old Hindu belief. It’s the origin of the universe theory: The universe started an arrhythmic event. The Big Bang occurred, and there was another sound after that, and that was the first rhythm. I talk about it in my book. So I'd have to believe that's my cosmology.