Is there an A&O Ball curse? After the late Elliott Smith’stragically painful performance in 2002 and the debacle at PattenGym last year that left Zwan and Queens of the Stone Age fans outin the cold after a fire marshal unexpectedly cut the gym’scapacity due to safety concerns, an ugly pattern seemed to beforming.

Luckily, Thursday’s Ball, featuring hip-hop acts The Roots andCommon at the Riviera Theater, dispelled any such talk of a cursewhile giving the Northwestern crowd much to cheer for.

The audience was more than 2,000 strong, but fell short of theRiviera’s capacity of 2,300, said A&O Chairman Brian Bockrath.Still, he said the ball was a success.

“When you see a crowd that size of mostly NU students, there aredefinitely a lot of empty dorm rooms in Evanston,” he said.

The Roots followed Common’s opening act with a unique set thatwas equal parts live hip-hop and party-pumping jazz band.

Starting off with a 45-minute set of originals, the instrumentalhip-hop group alive bumped out the jams with emcee Black Thoughtconsistently showing off his tounge-twisting rhymes. Along with thegroup’s new Knight Rider-sounding single “Don’t Say Nothing,” thecrew kept concertgoers bouncing their heads with songs including”Proceed” and “The Next Movement.”

In the second half of its set, the six-piece band transformedinto a house-party stomping jam band with extended solos from eachmember and a concluding session of hip-hop name that tune.

The Roots ended their set playing DJ to the eager crowd. Cyclingthrough snippets of current hits like Usher’s “Yeah!” and Jay-Z’s”Dirt Off Your Shoulder” as well as some old-school favorites likeAfrika Bambaataa’s “Planet Rock” and LL Cool J’s “I Need Love,” theband kept the crowd on their toes.

Before The Roots wide-ranging performance, Common kicked thingsoff with an hour-long set devoted to the essence of old-schoolhip-hop. With his bare-bones two turntables and a microphoneset-up, the Chicago emcee shined. A rapper’s rapper, Common kept itreal with his trademark honesty and charm.

Highlighting his lyrical abilities, the artist glided through anexcellent version of “I Used to Love H.E.R.,” a brilliantlymetaphorical ode to his first love — hip-hop.

A veteran emcee, Common still proved he had much to say with apolitically conscious freestyle that included the prickly line,”Burn a Bush ’cause for peace he don’t push the button.”

Both Common and The Roots paid homage to the past while pavingtheir own way Thursday at the Riviera Theater. With everyonenodding their heads in unison for most of the show, it seems likethe treacherous A&O Ball curse has been lifted thanks to someseriously funky music.