Nas, Foxy Brown Revive Supergroup The Firm Onstage

Reunion highlights opening night of blockbuster R. Kelly tour.

PHILADELPHIA -- The three major partners in rap supergroup the Firm -- Nas, Foxy Brown and AZ -- reunited Thursday during the opening show of R&B singer R. Kelly's blockbuster arena tour.

Nas, one of Kelly's high-profile opening acts, told fans at the First

Union Center there had been "bad blood" between the group, whose The

Firm: The Album was a 1997 chart-topper. Then he brought out Brown,

who had opened the show, and AZ to trade rhymes with him before announcing

the group would release a new album this year.

"We can't be fighting," Nas said.

It was a moment of pure hip-hop in a show otherwise dominated by R&B. Nas and Brown both performed, without video screens or full light shows, on a bare, curtained-off portion of Kelly's large, prop-filled stage.

Brown (born Inga Marchand), who wore skin-tight, glistening black leather

pedal pushers, high heels and a gray top, opened the show with a 15-minute set that drew a lukewarm response from fans. Many attributed that reaction to an incident in which the rapper was accused of insulting Philadelphia hip-hop fans on a local radio station a month ago.

Backed by a crew of dancers and a DJ, she ran through abbreviated versions of her raunchy hits, including "Hot Spot" (RealAudio excerpt) and quickly left the stage.

Nas (born Nasir Jones), who performed most of his set accompanied only

by a backup rapper and a DJ, was received more warmly. Still, many fans

stayed seated until his set closer, "Hate Me Now" (RealAudio excerpt), the apocalyptic-sounding first single from his third album, I Am, which has been one of the country's three top-selling albums since its release April 6.

Dressed in an all-white outfit consisting of a baseball cap, warm-up pants and an undershirt, with a large gold medallion dangling from his neck, Nas was a low-key presence, pacing casually back and forth as he rapped his complex, wordy lyrics with ease.

He played several other tracks from I Am, including the anthem "We Will Survive," which he dedicated to two fallen rappers, Tupac Shakur and Notorious B.I.G. He led the audience in chants dedicated to the pair's memory: "When I say '2,' you say 'Pac' ... When I say 'Biggie,' you say 'Smalls.' "

Nas also dipped into his back catalog, playing the fatalistic "Life's a Bitch" from his 1994 debut, Illmatic, among other older tracks.

He made no mention of rap mogul Sean "Puffy" Combs, who appears on the album version of "Hate Me Now"; Combs was arrested in April for allegedly assaulting Nas' manager, Steve Stoute, in an apparent dispute over the song's video. Introducing the song, Nas said, "If y'all believed in God, nobody gonna hate on you."

"Hate Me Now" was the last hip-hop song of the evening. Nas' set was followed by brief appearances by R&B singers Kelly Price and Deborah Cox, who paved the way for headliner R. Kelly.

In contrast to the slim production values of the opening acts' performances,

Kelly's set was replete with high-tech showmanship worthy of a pop superstar.

New video clips played on a giant screen throughout Kelly's set, which

featured numerous costume changes, a live band, a troupe of backup dancers

and singers, a pair of rappers and props that included a hydraulic lift and a giant bed.

Kelly played almost exclusively to the women in the crowd, adding seductive improvisational sections to his songs. "Who wants to know what it feels like to be in my bed?" he asked during "Half on a Baby," a slow jam from his latest album, R. (1998). His band moved into frenetic hard rock as Kelly and a half-undressed female guest disappeared under the big bed's red satin sheets.

Kelly skipped one of his biggest hits, "I Believe I Can Fly," but played several other radio favorites, including "Bump N' Grind," "You Remind Me of Something" and the recent "When a Woman's Fed Up."

Annette Lawrence, a 33-year-old fan from Philadelphia who said she was "not a rap person," judged Kelly's set "an excellent performance."

Rapper Busta Rhymes, who was scheduled to be on the tour, announced earlier in the week he was dropping out because he had not been allowed to put together the kind of stage production he wanted, according to a statement from his management.

After seeing the contrast in production values between Kelly's set and those of the opening acts, some fans said they better understood Busta Rhymes' decision.

Natalie Wallace, 20, from South Philadelphia, said the opening acts "could've used more [stage] props." She added, "I agree with Busta."

Thirteen-year-old Alfonso Ballard, also of South Philadelphia, said he sympathized with the rapper but was still disappointed.

"He should've come, regardless," Ballard said. "Busta was one of the main reasons why I came."