About 25 years ago, Academy Award-winning composer AR Rahman gave an austere musical expression to faith, an idea that has since become increasingly fraught in India’s public discourse.

In O paalanhaare, a Krishna bhajan in Ashutosh Gowariker’s Lagaan (2001), penned by Javed Akhtar and sung by Lata Mangeshkar, Rahman delivered a melody with rare tenderness. One that emerges at a moment of absolute despair, when the villagers pray for a solution. Looming over them is the idea of defeat in a cricket match with the British, which could force a community to pay three times the land tax. There is nothing dramatic in Rahman’s composition. The profundity is hidden in its simplicity.

Born Arunachalam Shekhar Dileep Kumar, Rahman lost his father and composer RK Shekhar, when he was nine and learned music as a session artiste. His family’s subsequent embrace of Islam would shape his spiritual journey, all of it allowing for music to be drawn from diverse devotional traditions.…