What do Bob Dylan, Cat Stevens, Madonna and Boy George have in common? They all got religion, and it doesn't matter which one, writes Andy Gill
It is, I suppose, an indictment of pop music's shallowness and disposability that so many of its practitioners eventually wind up looking to religion to fill the gaping hole in their lives. After all, if you need to turn to something as essentially insubstantial as religion to bring a little substance into your life, imagine how nebulous your existence must be in the first place. Such, perhaps, is the de-stabilising effect of living your life in a fragile bubble of PR hype: one prick and you're plummeting, grasping at angels for buoyancy.

In pop's infancy, the traffic was more likely to flow the other way: Sam Cooke, for instance, came in for terrible flak from former gospel colleagues when he left The Soul Stirrers to apply his talents to more secular ends. Luckily for us, it didn't stop him from inventing soul music, by the simple expedient of replacing expressions of love for "Him" (Jesus) with expressions of love for "her". Since then, hundreds have followed suit, from Aretha Franklin and Bobby Womack to Al Green and Whitney Houston - though curiously, any subsequent gospel work they may do is invariably inferior to their soul offerings. This is particularly so in the case of the Reverend Al Green, whose gospel records lack the soul-searing pain of his early Seventies soul classics. Clearly, he's happier in the arms of the Lord than any woman's embrace.

Madonna is the latest pop star to take the deity's shilling, though as a lapsed Catholic she might be said to have been fairly well primed for piety already. Her chosen religion is Kabbala and occult mystical tradition, which has its roots in 12th- century Judaism. One does wonder to what degree her choice was influenced by those groovy little swirly henna hand- designs - Sanskrit symbols, actually - through which, if I have understood The Daily Mirror's guide to religious hand-painting correctly, adherents can petition their lord for love, wealth, great sex and the other essential spiritual values.

One should not, I feel, overlook too readily the impact of design and dress upon religious choice, particularly when dealing with pop stars. After all, who wants to look like a frump on Top Of The Pops? This, perhaps, explains why so few musicians since George Harrison have gone in for Krishna Consciousness - those shapeless robes do nothing for one's pecs, and worse yet, suggest that you're really trying to hide the love-handles. Likewise, the Bhagwan has rather dipped in popularity through the last decade - after all, could there be a more hideous colour than the muddy orange with which Bhagwanites bedecked themselves?

Such, perhaps, are the kind of considerations that exercised the mind of Boy George when he was mentally strolling through the religious supermarket, basket in hand; mercifully, in Buddhism he seems to have chosen a belief that allows his natural exoticism to blossom in fully orchidaceous form. Though where exactly that leaves Sting, whose own chosen form of Buddhism appears to mandate the wearing of the most threadbare and down-at-heel of ash-coloured sackcloth sweaters, is anybody's business. Perhaps he is too busy having tantric sex for six hours at a time to actually go out and do a little shopping. Priorities, priorities...

In earlier decades, these kinds of choices involved rather more serious reflection, and more seriously affected a musician's work, than Buddhism appears to have on the music of Sting and Boy George, which remains essentially unchanged. Both Cat Stevens and the folk-rock guitarist Richard Thompson, for instance, took the giant step of converting to Islam in the Seventies, though with widely differing results. In Stevens' case, his becoming Yusuf Islam effectively silenced his singing career - for which legions of Seventies bedsit-dwelling boys, forced to listen to their girlfriends' copies of Teaser And The Firecat as a necessary prelude to more carnal overtures, gave belated thanks. Overnight, the once mild-mannered Cat became flintier of mien and less forgiving of attitude, even supporting the Iranian fatwa on Salman Rushdie.

Thompson's Sufism, by contrast, left his guitar skills and sense of humour completely intact. Ask Yusuf Islam why he converted, and you would no doubt be fixed with a steely gaze and subjected to a lengthy exegesis upon the appropriate passage from The Koran; but when I asked Thompson what attracted him to Islam, he answered, "Food! The food was great. I'm serious! I just thought, these people must be all right, because the food is incredible." Ahh, now you're talking my language - it'll be the Sufi and chips for me, please.

Nourishment, both corporeal and spiritual, clearly plays a big part in this religion business, though some musicians are looking for a little creative assistance - an extra hand on the keyboard, as it were. One hesitates to mention Scientology, for fear of being forced to marry Lisa-Marie Presley, but back in the Seventies, quite a few famous jazz-rockers signed up for it, on the supposition that it might help free up their creative juices. Since then, few notable musicians have followed suit - and those toying with the idea can usually be dissuaded by a cursory exposure to the endlessly tedious albums of Chick Corea. Unfortunately, L. Ron Hubbard appears not to have left instructions on how Chick's creative juices might be bottled up again, for the betterment of mankind.

The ranks of pious popsters are legion, from Elvis and Sir Cliff to U2 and, er, Dana, but one talent in particular stands head and shoulders above the pack: Bob Dylan. He is the closest pop music has to a serial converter, trying on one religion after another, especially those allowing the greatest opportunity for scourging of the wicked and casting-out of moneychangers. Born Jewish, Dylan led an agnostic life through his most creative period, claiming at the time, "Got no religion. Tried a bunch of different religions. The churches are divided. Can't make up their minds, and neither can I. Never saw a god; can't say until I see one."

Later on, he presumably couldn't stop seeing them: the birth of his children in the late Sixties led to an interest in his Judaic background, which is understandable; but then, in the late Seventies, following the conversion of a girlfriend, he followed suit and became a born-again Christian. In retrospect, this wasn't a great surprise, given that Dylan has always had something of the Old Testament prophet about him, but it was still a shock for audiences at the turn of that decade to find themselves being lectured by their former idol in full-blown trendy vicar mode, in songs with titles like "Property Of Jesus" and "Ye Shall Be Changed".

The effect was predictable, and from a mundane, materialistic point of view, quite disastrous. The trilogy of god-bothering albums Dylan recorded during this period did enormous damage to both his reputation and his commercial profile, virtually finishing him off as a chart act. Indeed, so poor were his prospects that when he offered his record company a live album culled from his gospel tour, they politely declined. Dylan's religious period should stand as a warning to other musicians musing upon the spiritual realm. Kids: just say no.