Sorry, haters, hip-hop isn't dead.

It may be in trouble, dogged by ongoing attacks on its language and imagery in the wake of Don Imus' racist remarks, as well as a 33 percent drop-off in the genre's sales for the first half of the year. But Rock the Bells, a 10-hour festival of nearly two dozen acts at Randalls Island throughout the weekend, not only provided plenty of proof of how potent the genre still is, but it offered a blueprint of ideas rappers could use to make hip-hop even more powerful in the future.

t begins with the music. The day's most entertaining acts used live musicians to give their performances extra spark -- the reunited rap-rockers Rage Against the Machine, the legendary Public Enemy, up-and-comer Pharoahe Monch, and the current generation's most consistently inventive act The Roots, whose nine-piece band even included a tuba.

Rage Against the Machine, reunited after seven years, sounded like it had never been apart, even though the world, musically and politically, is completely different. The brash, politicized directness of "Bulls on Parade" or "Killing in the Name" was never common, though it all but vanished in the post-9/11 world, along with singer Zach de la Rocha. (Though de la Rocha was uncharacteristically quiet between songs, he did take a moment to clarify a recent controversial position: He has not called for President George W. Bush to be assassinated. He wants him "tried as a war criminal and he should be hung and shot." "The real assassins," he added, "are Bush and Cheney.")

Like the rest of both the mainstream hip-hop and rock worlds, the rest of Rage Against the Machine has continued making music as Audioslave, but that sounds a bit muted, a bit hedged, compared to the unbridled passion shown throughout the band's 70-minute set. Tom Morello's churning guitar lines amplify de la Rocha's lyrical fervor in anthems such as "Guerilla Radio" in a way that hip-hop acts have definitely noticed.

Public Enemy has raised its rock quotient in recent years with its fiery band. "Bring the Noise," featuring an appearance by Anthrax's Scott Ian to add some thrash-metal guitar to the set, and "Welcome to the Terrordome" pack even more of a punch today with the current band lineup than they did originally.

Whether he is trying to put hip-hop in context or repping Strong Island, Chuck D still gives it his all, running across the stage at full speed, playing catch with his mike and selling the urgency of these songs better than the ever-growing crop of pretenders whose live show is little more than pacing the stage.