The college marching band, that benignly regimented music machine, has enjoyed a bit of a legacy in pop music, probably dating back to the title track of Fleetwood Mac's Tusk. But it isn't often you get to hear a marching band as supercharged and low-down, as rudely alive, as the one in Dave Chappelle's Block Party. On a makeshift stage at the end of a wide, crumbling alleyway in Brooklyn's Bedford-Stuyvesant neighborhood, Kanye West, looking casually dapper in a black T-shirt, sport coat, and gold chains, his body coiling and tensing to the beat, raps in what can only be described as a holy fury. At first, before you adjust to the velocity of his words, you may think that he's engaged in some sort of wily verbal assault. But then, just behind him, you catch the crooning of John Legend, as well as a chanted chorus (''Je-sus walks! Jesus walks!'') underscored by the stately, ominous hot-funk bounce of Ohio's Central State University band, whose players are arranged on the avenue nearby. West's rap is nothing less than a shout-out to God, and as you take in his confession, plus Legend's soaring plaint, plus the majestic blaring and swaying of the CSU band, the music surges to an ecstatic peak. All of a sudden, you remember what it's like when a concert movie isn't just glorified music-television fodder but, rather, an event that can restore your faith.
It helps that we got to see Chappelle, a few scenes earlier, sauntering up to the CSU band in the middle of a practice field in Dayton, Ohio, and asking the members, on the spot, to take a bus to New York and join the big rap/R& B concert he's organizing, which is set to take place on Sept. 18, 2004. With his shaved head, half-lidded eyes, and infectious grin that's always in danger of shutting off as quickly as it lights up, Chappelle has the look of a terminally mischievous cartoon bunny rabbit. In Dave Chappelle's Block Party, he exists in a perpetual limbo of satirical detachment, but only because he appears to be deviously fascinated by every person and situation he encounters. Like Richard Pryor, he's all feelers, with a mockery that flows, almost compulsively, out of his screwy generosity of spirit. Everything Chappelle does in this movie from strolling, with bullhorn in hand, through his hometown of Dayton, offering ''golden tickets'' to random citizens, to standing up on stage and telling the band, over and over, to ''hit me!'' as he lives out the fantasy of being James Brown with each jangly-hilarious ''hit'' is done on impulse, as an inspired whim. Yet it's all presented with such catchy, soft-shoe enthusiasm that the film effectively dissolves the line between audience and performer.
Dave Chappelle's Block Party is perhaps the first concert movie since Stop Making Sense to give you a blissful buzz. The buzz comes from the music, which has a loose, burning joy that's rare to behold in a live rap performance, and also from Chappelle's wicked prankster's glee, which spreads through the movie like a happy virus. Block Party features Chappelle as its impresario, on-scene jester, and guiding spirit, and the director, Michel Gondry, echoing techniques he used in Eternal Sunshine of the Spotless Mind, keeps cutting between the run-up to the concert and the event itself, staging the film as a series of flickering time leaps that work on you almost kinesthetically. After a while, you stop thinking about ''past'' and ''present.'' You're eager simply to be in the now, as content to watch a rapping Brooklyn waiter, who turns out to be a brilliant boaster, as you are to see an incendiary stage performance by Dead Prez, with their blistering indictments of white power.
The enthralling spirit of Dave Chappelle's Block Party, its mood of exuberant democracy, extends to every rap and soul performance in the film. A lot of the artists, like Kanye West or Common, summon an intensity of rhythm and attitude that didn't exist in hip-hop before the form went gangsta in the early '90s, yet all of them, in different ways, reject the get rich and f--- the world nihilism that ultimately brought gangsta rap to such a dead end. You can feel the longing for a more redemptive era when Erykah Badu, tearing off her Afro wig in the wind, does a gorgeous paean to ''back in the day when things were cool,'' and that spirit extends to Mos Def (who has the greatest dimples in rap), singing about his desire ''to be free,'' or the Roots, with Kool G Rap and Big Daddy Kane, playing the ferocious ''Boom.'' It's part of the rousing offhandedness of Block Party that the finale, in which Lauryn Hill, with her china-doll face and luscious tremolo, reunites with the Fugees to do ''Killing Me Softly With His Song,'' is sublime, but no more so than a follow-up scene in which Wyclef Jean, off stage, leads a group of those CSU marching band members in his great reggae anthem ''President'' (''If I was president...''), letting them and the audience know that, in music as in the world, anything is still possible.