Fugazi's performance Sunday night at the 9:30 club was a benefit for two local AIDS charities, so it made sense that the band performed "Give Me the Cure," a song from its 1988 debut. Otherwise, however, the emotionally direct style of the D.C. quartet's early days was seldom in evidence.

Instead, Fugazi continued in the deconstructionist mode of its recent work, dissecting such already skeletal songs as "Reclamation" and "Do You Like Me" into throbbing beats, shards of guitar noise and vocals that were alternately recited or howled.

At times, as when the band added clarinet and trumpet to a ponderous cadence, the sound could only be described as heavy-metal free jazz. Still, on those occasions when the rhythms, clamor and voices found their way back together, the effect was as thrilling as ever.

The Ex, the veteran Dutch post-punk quintet that opened the show, is also known for musical experimentation, but its set was firmly rooted in the angularly funky early-'80s British sound that still serves as Fugazi's foundation. As on the band's latest album, "Starters Alternators," the drums and guitars lunged and parried, yielding a musical locomotion that was cyclical yet straightforward.