Self-publicist, superficial preener or perverting pop idol, purple-loving Prince has had his critics in the last 30 years. But, as Brian Morton argues in his new book A Thief In The Temple, it is time the world joined the likes of Miles Davis and learned to appreciate one of the 20th century�s most productive and passionate musical artists

THREE weeks ago, Prince performed at the half-time show at Super Bowl XLI in Miami. There were no reports of a "wardrobe malfunction", of the sort that afflicted Janet Jackson and her weedy dance partner Justin Timberlake at the same event a couple of years before. This is impressive on two counts. The Super Bowl may not be the best music crowd on the circuit, but the invitation alone was a major sign of rehabilitation. This was the same artist - back then Formerly Known As Prince - who in the latter part of the Nineties couldn't get himself arrested and who'd become a kind of tabloid joke: the Purple Pain, Ponce, Princess, Squiggle. Whatever Scott Fitzgerald may have thought, there are second acts in American lives. While Prince's post-millennium albums - The Rainbow Children, Musicology, 3121- are no better or worse than solidly produced, eminently danceable soul-funk-jazz-rock, the figures don't lie.

Near bankrupt in the mid-Nineties and forced to sell off a raft of assets, a decade later Prince was again the highest grossing musical act in the United States, a turnaround largely based on getting his publishing rights back. That meant he was able to draw on a body of work that includes Nothing Compares 2 U and Manic Monday, which right now, somewhere in the world, today as every day, are getting radio play.

The other impressive thing about the Miami Super Bowl appearance was that when Prince started out 30 years ago, his whole career looked like a "wardrobe malfunction". This, remember, was the man who appeared in grainy black and white on an album cover wearing nothing but a trenchcoat, bandanna, black panties and a scowl. That was the aptly named Dirty Mind and though it took a bit of working out, you could see that he was posed up against naked bedsprings.

Though later he turned out some of the best bubblegum love songs ever - The Most Beautiful Girl In The World was written for first wife Mayte Garcia - what Prince offered wasn't romance or even sexual healing, but hard, nasty sex.

Prince showed up like an incoming missile (sexual puns and phallic shapes are an occupational hazard in this line of work) on the Moral Majority radar. In his home state of Minnesota, a pair of evangelical brothers, Dan and Steve Peters, ultra-strict constructionists when it came to biblical provisions for music (basically: Psalms of David, angelic trumps and choirs - good; everything else - bad), waged a campaign against the local boy, asking teenagers to help save the Twin Cities from turning into the Cities of the Plain by burning copies of Dirty Mind and Purple Rain.

Interestingly, the brothers no longer mention Prince on their website, instead promoting the evangelical songs of born-again Mark Farner (formerly of Grand Funk Railroad) and reserving their spleen for those faux-Christian acts that camouflage their commitment to the Devil's music with gospel choruses. For a time, though, he was their favourite whipping boy. Prince had, however, thrown the cultural conservatives a more lasting hostage to fortune. One evening in 1984, the wife of senator Al Gore, who 16 years later would win a presidential election, but still not make it to the White House, overheard their daughter listening to Purple Rain, the record/film that made Prince a superstar. She was shocked by the lyrical content. It would be entertaining to report that Karenna Gore was so thoroughly corrupted by Darling Nikki (a slice of cold funk that kicks off with an image of Nikki masturbating with a magazine) that she threw in her lot with Prince, took to wearing flimsy camisoles and basques and made a career as lead singer of Karenna 6.

Disappointingly, Karenna Gore is now a very serious and ardent Democratic campaigner. Her bedroom listening did, however, lead to Tipper Gore and Susan Baker, wife of the then Treasury Secretary James Baker, founding the Parents Music Resource Center which now provides the PARENTAL ADVISORY stickers intended to warn families of offensive content, but more often used by teenagers to determine whether there's anything really worth listening to on a rock or hip-hop album. Ironically, one of the first albums slated for such a sticker was Prince's infamous Black Album, which was pulled before release.

The exact reason why the actually quite average Black Album took almost a decade to get overground, by which time it was one of the bestselling bootlegs ever, will probably never be known. Speculation from the notion that Prince had got religion (which he later did for real, joining the Jehovah's Witnesses) and had repented his saucy past, to the fact that he didn't think it was good enough, or that it contained secret messages of a diabolic nature.

The simplest truth is that Prince was locked in conflict with Warners, the record label that had given him an unprecedentedly free hand to write, produce and play all the instruments on his first record For You, but who were now trying hard to rein in (rain/reign puns also figure prominently) a man who had delivered one huge crossover hit but who seemed disinclined to keep to the winning formula.

Prince has always had the ability to gloss bland fact with an aura of mystery and scandal. With The Black Album, it worked. Probably only Lou Reed's Metal Machine Music created a greater musical cult out of the rubble of contractual squabbling. But in every aspect of Prince's life, legend wins out over bare truth.

He's now nearly 50, into a second marriage, to Manuela Testolini, and both his parents are dead. He even tried to reinvent them. John L Nelson was a jazz pianist who named his son after his group, the Prince Rogers Trio. His mother was Mattie Shaw Nelson, and had been an amateur singer. It seems the two had a very stormy relationship. They divorced and though he seems to have quarrelled with his father, Nelson did collaborate on some of the material for later records. Both died a few years ago. Prince liked to suggest that Nelson was half-Italian and that his mother, who'd also come up to Minneapolis from the south, was white, Native American and "a bunch of other things" (she is played by a Greek actress in the film of Purple Rain). None of it was true as they were actually light-skinned black people. But Prince's version sounded more exotic, and perhaps helped gloss over the pain of their separation and his virtual adoption by a neighbour Bernadette Anderson.

Prince also pretended he'd lived rough for a time, and it offered background to his desire to create a music that not only broke the rules of traditional black R'n'B (like taking the bass line out of When Doves Cry and Kiss) but also attempted to blend it with jazz, white pop, Joni Mitchell and the Beatles - hence The Black Album.

It was a unique and intoxicating mix. The critic Robert Palmer talked about Prince's musical "bi-racism". Unlike Michael Jackson, who simply lightened his musical skin as well to reach out over the pop/R'n'B divide, Prince played with ideas of colour, quite explicitly in another movie, Under The Cherry Moon and its soundtrack Parade, and in virtually all the work from Purple Rain onwards.

If Prince's guitar style - and he is arguably the finest rhythm guitarist ever - derives less from Jimi Hendrix than from Carlos Santana, his approach to music-making is a curious mixture of old-fashioned songcraft and the abstract/improvisation of Miles Davis, an admirer and friend before the trumpeter's death in 1991.

Claiming to be interested in Prince because of his association with Davis is a little like pretending you buy Playboy for the articles. I wasn't quite a Prince fan from day one, because in 1978 For You made only the tiniest splash over here, but I've certainly been on board since Dirty Mind recalibrated my expectations of pop music a couple of years further on, and in the process established a musical benchmark for the new decade that no one else ever quite reached.

Now that Prince himself is approaching his half-century, it seems slightly less anomalous that a middle-aged white guy should be writing about him. Apart from his virtuosic blending of styles, the other thing that intrigued me about Prince was how radically he reworked the sacred-and-profane cliché. There has always been a Saturday night and Sunday morning element in black music, a sense that after the hedonism, you have to get down on your knees and pray.

You find it in Little Richard and in the Reverend Al Green. It might be argued that Prince simply pushed the poles further apart, vigorously stroking his guitar and dry-humping girl singers one minute, singing The Cross the next. Fact is, that having grown up in a mildly Protestant, mostly white mid-West city, Prince had less of a background in the church and church music than most R'n'B and soul artists. In one respect, he was closer to Marvin Gaye (a parallel rarely mentioned, strangely) in wanting to find a position between hedonism and responsibility, between Sexual Healing and What's Going On?, you might say.

It's very difficult to sell people who know only the tabloid and Chart Show version the idea of Prince as a political or socially aware artist. Seeing him posed naked on the cover of Lovesexy, looking like a cross between a forest spirit and a rent-boy, doesn't help, but delve a little deeper and it's clear that Prince has never just been content to have a rockin' good time and then make amends with a hymn and a prayer.

There is a deep vein of social conscience running through his work. Again, this may be the legacy of a Minnesota upbringing, one of the few impeccably liberal states in the Union, but it also comes from the same deep source as Miles Davis's activism, which, beyond titling late albums Tutu and Amandla, was rarely made overt.

When Prince wrote "SLAVE" on his cheek in eyebrow pencil, everyone laughed at what seemed like a contractual flounce, another chapter in the battle with Warner's that had him replace his name with an unpronounceable symbol that combined the astrological signs for male and female. But no reference to slavery can ever be trivial in black discourse and changing one's name has deep historical resonances, as when Cassius Clay abandoned his "slave" name and became Muhammad Ali. Interestingly, the only world religious tradition Prince doesn't seem to have dabbled in, amid all his aural and visual references to Buddhist and Hindu beliefs and his recent trawls through the Witnesses' New World Bible, is Islam - liberal, Black, fundamentalist or otherwise.

For Prince, Warner-Chappell's ownership of his name and his songs was a form of enslavement and he kicked against it. Tellingly, the main tabloid score against him was that the word was written with a cosmetic stick. Perhaps if he had carved "4 real" into his forearm, they'd have taken him more seriously. With that shift of perspective, look back through the catalogue on songs and albums and a rather different Prince begins to emerge. With Dirty Mind and for a time afterwards, Prince begins to dateline his records Uptown, which seems to be both place and no-place, a virtual constituency of like-minded musical gypsies and renegades, roots of the group that became The Revolution and later the New Power Generation; one can almost imagine those as names armed insurrectionary cells. Though Uptown has real-life equivalents in Minneapolis, it also carries an element of Utopia, which is recast as dystopia in the highly political Controversy (with its Annie Christian Antichrist figure), as apocalypse on 1999, and dissolved into a kind of Nirvana on Around The World In A Day.

It surfaces again, though, on Prince's third masterpiece album. Sign O' The Times begins with a chilling - and twice chilling because delivered in such an offhand way - list of urban ills, from needle-sharing and AIDS, to poverty, to gang violence. If this is party music, it is, as someone once said, a strange way to party.

Compare Prince's social and political commentaries with Michael Jackson's vapid one-worldism and it's clear Prince grounds his fantasies in tough realism, just as he grounds his songs in a flawless instinct for harmonic form and melody. By contrast, Jackson sings into Sony Pro and hands the tape (but not the composition credit) to Quincy Jones.

Prince has learned the toughest lesson of all in showbusiness: how to grow up in it and to do so with - and this might seem a strange way of putting it - considerable dignity. There has been carefully positioned scandal along the way, like the night at the pitch of his post-Batman affair with Kim Basinger when the Paisley Park engineers came in the next morning to find the mixing desk clogged with honey or syrup; like his apparent transformation of former student teacher Sheena Easton into a sex-mad siren, singing about her "Sugar Walls". Not even Esther Rantzen could have pulled off that kind of transformation. But no real, hurtful scandal and certainly nothing of the kind that has haunted Janet's brother.

The only Prince headlines involving children came when his and Mayte's child was born with a severe cranial abnormality and died a few days later. There is some evidence that Prince may have had epilepsy in childhood, which may explain his short stature and might have been a factor in baby Gregory's congenital problem. The couple were clearly in grief, but Prince pressed on regardless with an album release - one track allegedly included the baby's foetal heartbeat - told Oprah that the baby was fine and announced some weeks after the child's funeral that he was "enjoying fatherhood". All of this might have been inept and a bit strange, but hardly up to becoming entangled with young children and then buying off their families.

Prince may well be the most important figure in popular music of the last generation. He is a thief in the temple in that he has stealthily stripped virtually every available style of anything that can be of use to him and done so with a courageous mixture of reverence and iconoclasm. He has very few obvious disciples largely because he is too protean and too instantly identifiable - in the manner of that other mercurial Minnesotan Bob Dylan - to be copied.

The truly impressive nature of Prince's achievement may not even be known until after his death, if indeed he allows it to be made public then. Much as the reclusive JD Salinger is said to have a safeful of unpublished manuscripts in his high-walled house, so the Princely fortress at Paisley Park, on the outskirts of the native city he's never left, is said to house literally hundreds of unrecorded songs, demos, jam sessions, collaborations, doodles, sketches, scripts, stories and diaries. For all the headlines, smoke and mirrors, Prince is not so much committed to as possessed by music. When he projected his own future, 15 years ago, it sounded as much curse as promise: "a song every day for the rest of my life".

Prince: A Thief In The Temple by Brian Morton is published next month by Canongate, £10.99