Few people recognised the tiny figure in a garish suit hovering beside Beyoncé Knowles at the recent Grammy awards in Los Angeles. Then the signature strains of Purple Rain blasted out and an arc of electricity crackled around the world as the star ripped through some of his greatest hits.

After years in the wilderness, Prince is back. A world tour and a new album, Musicology, out tomorrow, are reviving memories of the man who redefined pop in the mid-1980s with a funky, sexy, often sleazy range of talents that eclipsed every performer on the planet.

With hits such as Kiss, Let’s Go Crazy and Little Red Corvette, Prince laid claim to the legacies of Curtis Mayfield and Sly Stone while dipping into the psychedelia of Jimi Hendrix and adding his own brand of explicit erotica. A complex and fascinating personality, the “purple poseur” brought the flamboyant stage presence of a wild-eyed libertine whose bombast and sexually ambiguous swagger contrasted with the professional care of a disciplined perfectionist. For good measure, he was also a painfully shy introvert.

Some critics have pronounced Prince’s new tracks his best work since his last great single, Gett Off in 1991. Fuelling the buzz is a tour that began in Reno, Nevada, last weekend and will reach Britain at some future date, as yet unspecified.

At last, the mercurial artist formerly known as the Artist Formerly Known as Prince has broken his self-imposed ban on performing his most famous hits. Now known once again as Prince, he is giving his fans the old numbers live “for the last time” — which in showbiz parlance means until the next time he needs to relaunch himself.

The impression that Prince Rogers Nelson has finally come to his senses at the age of 45 was reinforced last month, when he was inducted into the Rock’n’Roll Hall of Fame in New York. Yet, at the same time, his eccentricity seemed to have returned in his devotion to the Jehovah’s Witnesses, the Christian fundamentalists who reject all other denominations and believe in the imminent end of the world.

Of course, a bit of spirituality is almost a rite of passage for pop’s aristocracy. Al Green and Little Richard got religion (so did Cliff Richard, permanently). Madonna has become an adherent of kabbalah, an offshoot of the Jewish faith, while George Harrison and Boy George joined the Hare Krishnas. But Prince’s zeal is of a different order.

A note of hilarity crept into reports that one of the most lascivious figures in pop was knocking on doors in his home town of Minneapolis to ask astonished residents: “Would you like to talk about Jesus?” In one celebrated incident, he stepped out of his limo with four bodyguards and his friend Larry Graham, the former bass player in Sly and the Family Stone, and approached the home of a Jewish housewife.

She reported: “Door bell rings. My husband runs upstairs and says, ‘Prince is at the door!’ I say, ‘No way! This is Sunday and it’s the night of Yom Kippur’. My first thought is, ‘Cool, cool. He wants to use my house for a set. I’m glad. Demolish the whole thing!’

“Then they start in on this Jehovah’s Witness stuff. I say, ‘You’ve walked into a Jewish household and this is not something I’m interested in’.” Nevertheless, Prince stayed for 25 minutes of Bible readings and handed her a pamphlet.

His conversion has been attributed to a turbulent series of events that began with the death of his son, followed by his divorce from his first wife. Within weeks of his marriage to Manuela Testolini, his former assistant who, at 27, was 18 years his junior, came the death of his mother, whose last wish was that he became a Jehovah’s Witness. His father had died six months earlier.

The singer claims that he has a new set of values. “My song Darling Nikki was considered porn because I said the word ‘masturbate’. That’s not me any more,” he declared.

There is much to atone for — the four-letter words, the belief in salvation through sex, the string of girlfriends that included Sheena Easton, Madonna, Kim Basinger and Carmen Electra — but most notably the professional perversity that has kept him the shadows for so long.