Last year, rap group Public Enemy was inducted in the Rock and Roll Hall of Fame, but Friday on the Congo Square Stage, original members Chuck D, Flavor Flav and Professor Griff showed they’re not a nostalgia act.

The set leaned heavily on the group’s classics, but the sound was augmented by a live band and DJ Lord. The energy came from the beats, aggressive samples that remain confrontational, and Chuck D’s stun gun of a voice.

Because Jazz Fest prides itself on being a family festival, Chuck D and Flavor Flav had to watch their language. That led to some unintentionally comic moments as they used initials or sounds where they would swear.

“---- the game if it don’t mean nothing,” Chuck D said, criticizing the radio and celebrating hometown heroes Allen Toussaint and Fats Domino among others.

Flavor Flav remains a wild card. He brought Chuck D’s mom onstage to wish her a happy birthday, and he dedicated “31 Flavors” to his lawyer, “who helps me with my cases.”

Being in New Orleans clearly meant a lot to Chuck D, who dedicated “Timebomb” to The Meters and declared the city “the home of all music.” As uneasy as he seemed with modern technology, he announced his Twitter handle before the set’s end.

By the time Flavor Flav took “Fight the Power” into the crowd, Public Enemy had reinvented classics, done push-ups, quoted Led Zeppelin’s “Kashmir” and showed the sort of vitality we want from any band, much less a 25-year-old one.