Which brings me back to Sufism. Sufism is a sect of Islam, but they sit uneasily on opposite sides of the divide I've just described. Sufism is a pluralistic, transcendental, and tolerant religion, stressing love as the path to the divine, not fear. They use beautiful and trance-inducing music as an important part of their worship, to help followers reach an ecstatic and transcendental unity with god. Sufis welcome everyone, regardless of their faith or past history. I don't mean to imply that traditional Islam is the opposite of all these traits, but I think it's fair to say that it's stricter and more prescriptive. During this fascinating program, William Dalrymple talked to a traditional Islamic religious leader about their attitude to music. He asked why music was so frowned upon when the Islamic world had produced some of the most talented musicians in the world. The man half-smiled sadly and said that they were wrongdoers and would be punished.

Meanwhile, back at the Sufi temple, an annual festival celebrating the anniversary of the death of an important Sufi saint was in full flow. The temple was literally dripping with brightly coloured neon lights and fairy lights, and the courtyard was packed with smiling, laughing people. Wonderful, primal, infectious music filled the night air, and people whirled, danced, threw rose petals around and hugged one another. On the surface, at least, it would be difficult to recognise these two religions as stemming from the same root.

As regular readers will know, I'm not religious, but have a strange fascination for religious music of many kinds. I've long adored the style of Qawwali popularised by the late, great Nusrat Fateh Ali Khan, but the programme also introduced me to the different styles of Sufi music from Morroco, Syria, India and Turkey. Each style was strikingly different from the rest, but all were life-affirming and ecstatic, and made me want to go and hear them live for myself in Morocco or Pakistan.