It takes a certain arrogance to write a pop song about the simple thrills of pop music. U2 tried it a few years back with " Discotheque, " a cheap Chemical Brothers knockoff from their failed dance-music experiment, Pop (Island). Madonna did it last year with the brilliant title track to Music (Maverick), which laid to rest any fears of her popular demise with one question: " Do you like to boogie-woogie? " Now ’N Sync have joined the party with " Pop, " the lead single from their third and latest disc, Celebrity (Jive). " When your body starts to rock/And baby you can’t stop/And the music’s all you got/This must be pop, " sing the fab five. In other words, they like to boogie-woogie — and they know you do, too.

All three songs are giddy enough to charm despite their essential arrogance — even silly old " Discotheque, " which set a precedent for the other two by plundering the Eurodance underground for mindless fun way back in ’97. But ’N Sync have one major advantage over ’80s relics like U2 and Madonna, and that’s currency. Right now, they’re as big as pop stars get: early reports had Celebrity falling just short of the 2.4 million copies the group’s second disc, last year’s No Strings Attached (Jive), sold in its first week, giving them the two fastest-selling albums of all time. If anybody’s earned the right to sing to us about just how much we love their music, it’s ’N Sync.

And with Celebrity, they’ve made the first album of the current teen-pop explosion worth loving as a whole — not just for a couple of singles. It’s glitzy and mischievous in some parts, tender and heartbreaking in others, and sonically adventurous throughout. It boasts a top-notch list of hitmaking producers (BT, Rodney Jerkins, the Neptunes, Brian McKnight). And — in a first for the group or any of their contemporaries — designated songwriters Justin Timberlake and JC Chasez helped pen 10 of the disc’s 13 tracks between the two of them. You might be able to accuse Backstreet Boys of treading creative water these days, but not ’N Sync.

The BT-produced " Pop " is the first ’N Sync single written by Justin and noted teen-pop choreographer Wade Robson, a collaboration that proves to be a fruitful one over the course of the album. Jerkins brings the funk on the title track, which finds the boys lashing out at golddiggers and commenting slyly on the vacuous nature of their fame. Justin and the Neptunes address the standard boy-band issue of wooing a girl away from her loser boyfriend on " Girlfriend " as a mellow, live-sounding rhythm track sways in the background. Justin gets to show off his soulful (albeit occasionally overwrought) vocals on " Gone, " an aching torch song and his most impressive songwriting contribution.

Previously the group’s most experienced songwriter, JC gets second billing to Justin this time around. But he gamely holds up his side of the deal, and the one collaboration between the two, " Up Against the Wall, " is a lusty two-step tale of dance-club seduction that turns out to be the hottest jam on the album. " Now America will know two-step, " writes Justin to producers Riprock ’n’ Alex G in the liner notes. Self-congratulatory, yeah, but it is pretty cool hearing the biggest group in the world absorb a predominantly underground sound so successfully. JC goes from cutting edge to conventional on the McKnight-produced keyboard ballad " Selfish, " a worthy counterpart to Justin’s " Gone " on a disc that’s refreshingly light (for teen pop) on mushy ballads.

There’s plenty of other action for the kids, including the JC-penned video-game dud " The Game Is Over " and a guest appearance by Justin’s idol Stevie Wonder, who plays harmonica on the treacly ballad " Something like You. " In fact, Celebrity is so full of excitement that there’s not a single Swedish surname in the songwriting credits until track #7 — and the disc doesn’t even suffer for it. When dance-pop melody man Max Martin finally does show up on " Tell Me, Tell Me . . . Baby, " his vapid meditations on romantic angst seem retro next to the minimalist explorations that make up the rest of the album. The second-string Swedes who wrote the old ’N Sync smash " Bye Bye Bye " contribute the disc’s sparkliest Europop number, " Just Don’t Tell Me That, " but it gets buried even deeper into the disc.

Neither tune is bad, which may be the ultimate compliment to Justin and the boys. Prefab boy bands aren’t supposed to outgrow the system, but that’s exactly what they’ve done. " The thing you’ve got to realize/What we’re doing is not a trend, " sings Justin on " Pop. " It’s a scary thought, but he might be right.