This Sufi message of love, he points out, is what unites both of India's major faiths. "On a visit to the pilgrimage spot of Hajji Ali, you will find both Hindus and Muslims worshipping there." For Rahman, religion is a family affair. His mother, wife Saira, and their two daughters, Kateja, 5, and Rafia, 2, are as observant as he is.

Rahman's richly melodic score for the upcoming film "Zubeidaa," set in the 1950s, has made the composer nostalgic for the slower pace of the past. The music celebrates the classic scores of those golden days of Indian cinema, with slow symphonic orchestrations and the voice of Lata Mangeshkar, India's Nightingale. "Most of the scripts those days had a completeness to it. Now we are catering to the masses, and it's almost like fast food."

But Rahman is also thinking about the future. Ask him if he thinks he has struck upon a new audience for his music in the West, and he says in his self-effacing way, "Not only for my music, but I think the whole Bollywood thing is opening up." This impish Sufi devotee is blazing the trail.