YOU DO not need to travel too far from the Hard Rock Hotel to find the tacky glamour that earned Las Vegas its reputation as America’s real-life Sin City. The suite where The Who’s John Entwistle died in 2002 may not be on public display, but plenty of cheesy pop memorabilia certainly is. Jimi Hendrix’s guitar, Madonna’s bra and Britney’s schoolgirl costume from her Baby One More Time video hang in glass cases around the hotel’s casino floor.

Established as a virtually lawless railway outpost in 1905, Las Vegas is currently celebrating its 100th birthday. Tom Jones, Elton John and Tony Bennett are all in town to play mega-shows. Meanwhile at the Joint, the Hard Rock’s in-house concert venue, Coldplay, Motley Crüe and Billy Idol are all scheduled to join the festivities. But tonight Moby is the main attraction — and my reluctant Vegas tour guide.

He stumbles into the glaring Vegas sunlight as if he’s just stepped off a spaceship. A trip to the Hard Rock’s artifical beach, where loud music blasts bronzed Baywatch torsos, has left him queasy.

“The men had been sculpting their bodies for years, and the women had all had Botox and liposuction and plastic surgery,” complains the Woody Allen of techno-pop. “And I’m a bald skinny white guy from New York . . .”

Sin City holds no great allure for Moby, a vegan among meat-munching Las Vegans. “The first time I came here I had visions of Elvis and the Rat Pack,” he says. “I imagined an odd, degenerate glamour. But after seven or eight visits I’ve never seen anything remotely glamorous about Las Vegas. It’s hard to feel excited about gambling when you’re at the nickel slots in between a 75-year-old woman with emphysema and some truck driver who’s been there for three days on a crystal meth bender.”

In a bid to help the most earnest man in pop appreciate the seedy appeal of Vegas, I am taking him on a tour of the city’s scuzziest rock landmarks. A pearl-white limousine three blocks long has been hired. For one day only we are pimping Moby’s ride.

We cruise downtown, past the anonymous junction on Flamingo Road where the rapper Tupac Shakur was shot dead by unknown assassins in 1996. Past the Liberace Museum, a riot of sequin-studded grand pianos and preposterous peacock robes. Past the Elvis-a-Rama Museum, which is nowhere near as tacky, sadly. Just shabby.

The ghost of Elvis still rules this city, from the vast Hilton International, where he played 837 sell-out shows, to the achingly twee wedding chapel Little Church of the West, where he married AnnMargret in Viva Las Vegas. Since then Bob Geldof and Paula Yates, Noel Gallagher and Meg Matthews, Richard Gere and Cindy Crawford, Chris Evans and Billie Piper, and even Britney have all begun ill-fated marriages here. Off screen, the King wed his real child bride Priscilla around the corner, at the old Aladdin hotel, in 1967.

Moby begins to talk with macabre relish about the “impacted faeces” dug out of Presley’s lower intestine after his death, but a billboard of Celine Dion distracts him. “Why do they still do it?” he frets. “If you’ve sold a hundred million records and you’re Celine Dion, aren’t there better things you can do with your time than shows in Las Vegas?” Nothing on earth prepares you for the Strip, the throbbing spine of Vegas. A man-made Monument Valley of gargantuan casino hotels, each more psychedelically overblown than the last, it easily dwarfs the totalitarian kitsch of Stalin’s Russia or Ceaucescu’s Romania. Lined with post-modern theme-park parodies of Rome, Paris and Venice, there is something truly breathtaking about the Strip’s utter contempt for the history and geography of Old Europe.

Even Moby, finally, seems impressed. “It just boggles my mind,” he concedes. “That complete disregard for the truth of the places they’re trying to plagiarise — there’s something endearing about that. At least if something’s going to be bad, you want consistent badness, and Las Vegas does provide consistent badness. I have friends who comehere just to go on psychedelic drug benders.”

Modern-day Vegas may have a former Mafia lawyer, Oscar Goodman, as its mayor, but the city has allegedly cleaned up its act since organised crime ran the Strip during America’s postwar gambling boom. It is now a family-friendly holiday destination, Moby notes glumly, full of “senior citizens gambling away their pension money and couples having compromised sex”.

But at the far north end of the Strip, sanitised New Vegas still jostles with retro-sleazy Old Vegas. In the shadow of the futuristic new Wynn resort hotel, a billion-dollar bronze blade slicing the city’s skyline, gaudy billboards proclaim the dubious delights of bikini bull-riding, mud wrestling (“cold beer, dirty girls”) and the Mob-themed Ba Da Bing dining experience: “murder, music and a meal every night”.

Bus shelters groan under flyers for prostitutes, while bunker-like lapdancing clubs sport bracingly lowbrow signs: “Beaver Las Vegas” anyone? Amid this tawdry majesty stands a strikingly geometric Catholic cathedral, its design late-period Star Trek Modern, its mural promising Prayer, Peace and Penance. When Moby steps out of the limo to pose for pictures, a monster truck full of burly beerboys glides past. “Hey, Moby!” comes the inevitable cry. He waves back sheepishly.“You’re a f****** douche bag!” they scream before screeching away. Just another drive-by shouting. Moby shrugs. He is used to attracting such heated reactions. “The thing is, as much as they loathe me, they really love fame,” he sighs.

Beer and loathing in Las Vegas comes as no surprise.

At his Hard Rock show that night Moby is in party mood, improvising a medley of lounge-style cover versions just for the Vegas crowd. He brings the house down. Ain’t that a kick in the head? Later still, deep in the bowels of the hotel’s palatial basement nightclub, Moby appears to have finally learnt to enjoy Sin City. In the club’s VIP area he has beautiful young ladies virtually undressing in his lap. It appears that pop’s most earnest star is not so allergic to the pleasures of Las Vegas after all. When we bid him goodnight, the two seem to be getting along just fine.

• Moby’s new single, Spiders, is out now (Mute). He plays the 02 Wireless Festival in London next Friday. www.wirelessfestival.co.uk .