"We take it back to the days of yes y'allin,' " Jurassic 5 rhymed to the sold-out House of Blues, effectively drawing out the blueprint for the Cali-based hip-hop collective's success: old-school hip-

"We take it back to the days of yes y'allin,' " Jurassic 5 rhymed to the sold-out House of Blues, effectively drawing out the blueprint for the Cali-based hip-hop collective's success: old-school hip-hop upgraded for the 21st century.

True to form, J5's vibrant and intense set had all the makings of a mid-'80s park jam, spraying street corner braggadocio and lightning-quick wordplay over funky beats. But this was no nostalgia-fest: J5 prefers to deal in progressive hip-hop, and on this night it provided a wildly successful taste of a rap future that integrated the best parts of its past. For 90 hot minutes—epic in the age of the 25-minute rap show—J5 spat, scratched, bounced, and rocked the house. Live hip-hop doesn't get much better than this.

The night was also a sort of homecoming for MC Chali 2na, the thunder-voiced South Side native who served as a true master of ceremonies for the evening. Thanks both to his hometown affiliation and Darth Vader baritone, 2na found love from the crowd with every verse, particularly when he dug into the catchy, bouncing-ball groove on "Jurass Finish First" and the synth-loaded "What's Golden." And he did it all with a huge Will Smith smile and buckets of good cheer; the man could be a superstar.

And that's not to take anything away from J5's other rappers. With four MCs and two incredible DJs, J5 takes its cues from the early-'90s reigns of such groups as the Beastie Boys, De La Soul, A Tribe Called Quest, and the Pharcyde. It all translates into a chemistry that can only come from 10 years together: 2na, Zaakir, Akil, and Marc 7's laser-quick mike-swapping on "Break" had a dexterity rooted in experience and sweat.

One can only guess what J5 will do this summer on Lollapalooza. Not only did it make an argument for status as one of the best live hip-hop groups on the planet, the group traded in a love that was almost as thick as the beats. They took it back to the day, but they also lit the way to the future.—JV