The Art Ensemble of Chicago has gone on in the face of adversity for 50 years; it certainly wasn’t going to let a Secret Service logjam stop it.

Some protectee or another was at the Kennedy Center on Saturday night, giving rise to a security nightmare. The 18-piece icons of experimental jazz — led by saxophonist Roscoe Mitchell and drummer Famoudou Don Moye, the last survivors of its classic lineup — ignored it, performing a landmark anniversary concert that easily outdid its anniversary recording from earlier this year.

Where “We Are on the Edge: A 50th Anniversary Celebration” felt staid and insular, the performance at Kennedy Center’s Terrace Theater was both liberated and liberating, and it connected completely with the audience. It could simply have been the live environment: While the album’s second half is live, the ensemble’s performance art aspect doesn’t come through. Several of the musicians onstage, for example, wore face paint, though none so distinct as Senegalese percussionist Dudù Kouaté. After a lengthy, spacious piece that was as much contemporary classical as jazz avant-garde, Kouaté stepped up to steal the spotlight. He performed a ritual that involved a chant, an African brush and what appeared to be chalk dust blown into the air before plucking at a ngoni (a West African guitar-like instrument) and driving the Art Ensemble into a droning tune.

Pianist Brett Carson and flutist Nicole Mitchell provided most of the drone as the rest of the action in the piece came from Moye, Kouaté, and their fellow percussionists Enoch Williamson and Babu Atiba. As they played interlocking African grooves, the audience offered up a sea of gyrating necks and shoulders.

It was the percussive stuff that won out in shaping the concert. Pieces such as “We Are on the Edge” still had some strange, atonal harmonies (mostly from flutist Mitchell and the string section of violist Eddy Kwon, violinist Jean Cook and cellist Tomeka Reid), but the percussionists’ thump and Moor Mother’s equally thumping spoken-word performance dominated.

When Roscoe Mitchell brandished his sopranino sax on the piece just after “Edge,” it was in short staccato bursts of honk and screech that created a unique layer of syncopation. And it wasn’t just the percussionists who were girding the performance, but the triple basses of Junius Paul, Jaribu Shahid and Silvia Bolognesi, all of whom did vamps that one could feel in one’s chest.

In short, it was an evening of challenging music that was soaked in groove of the most contagious, overpowering kind. Even a slow-boiling, apparently timeless piece for flute, strings and the vocal acrobatics of baritone Rodolfo Cordova-Lebron had an odd momentum of its own that worked to segue into the Art Ensemble’s longtime, eminently danceable closer “Odwalla (The Theme).”

When it ended, the audience howled in vain for an encore. Nobody wanted it to be over, and not just because we feared the security phalanx.