BOSTON -- Both tricks and treats were in store when it came to celebrity cameos at the annual Jam'n 94.5 (WJMN-FM) Monster Jam, where Jay-Z, P. Diddy and Eve drew a full house of hip-hop fans to the FleetCenter Sunday.

The big news was that headliner Jay-Z had brought along Beyoncé Knowles to perform their new song, " '03 Bonnie & Clyde," but the Knowles affair was a bust. Radio station representatives reported that the singer was in the house, but she was never called onstage.

Sean "P. Diddy" Combs, on the other hand, helped Jay-Z put the bang in the Monster Jam with a surprise guest list of former, current and future associates. The artist formerly known as Puff Daddy arrived as a looming silhouette behind a fog-shrouded scrim, then stalked the stage in a leather jacket and shades while sparklers and flame geysers shot up around him.

But the real fireworks in Combs' third trip to the Monster Jam came from brief duets with such famous friends as Foxy Brown, Mary J. Blige and Busta Rhymes, who brought the set to a fever pitch with his free-for-all pogo through "Pass the Courvoisier" with his sidekick Spliff Star.

Finally, Diddy brought out Boston's R&B/pop veterans New Edition, announcing them as the latest signing to his Bad Boy label, and saluted departed hip-hop/R&B stars including Tupac Shakur and the Notorious B.I.G. with a sing-along of "I'll Be Missing You."

Jay-Z's more down-to-earth set delivered bass-heavy beats and fleet rhymes, both solo (in an opening "Izzo" and a poem about a dream about Biggie) and in potent tandem with Roc-A-Fella henchmen Beanie Sigel, Memphis Bleek and protégé Freestyle. "Heart of the City" sparked a crowd sing-along, and the set ended in a wild hail of balloons and confetti.

Ludacris kept his set lively with saucy rhymes and a jaunt into the security pit to slap fans' hands, and Eve invited several fans onstage to dance along to "Who's That Girl?"

And the girl named Beyoncé certainly wasn't missed by Jay-Z fan Monique Lacy, 19, of Cambridge. "I don't want to cry," Lacy said. "He needs me, not her."

For more sights and stories from concerts around the country, check out MTV News Tour Reports.