I have to admit that my expectations for Jello Biafra and his new band, the Guantanamo School of Medicine, were not especially high going into their recent stop at Europa, a Brooklyn Club that seems to specialize in vintage punk bands when it’s not operating as a Polish disco. I mean, Biafra’s musical output since the Dead Kennedys disbanded, which has included working with the Melvins and Al Jourgensen, has never approached the same dizzying heights of his original band’s spitfire, instead seeming to only aspire to be an acceptably spirited framework for Biafra’s ranting. And the melding of the lowest common denominators between thrash and hardcore by openers Star Fucking Hipsters and Witch Hunt did little to dissuade those notions. Hell, our hero’s now well into middle-age, when the body starts not being able to keep up with the mind’s demands.

But Jello and his capable crew soon laid waste to any questioning of their veracity. While Biafra, who hit the stage in a blood-streaked butcher’s smock, may have a little more jiggle to his middle, the guy’s barely lost any vitality, frantically pantomiming throughout and singing with all the bluster of his unmistakable whine intact. As “Strength Thru Shopping” shifted to “The Terror of Tinytown” (both from the band’s recent Audacity of Hype), he took off the smock to reveal a shirt sewn from Old Glory, a clear sign that he’s ever the provocateur.

But it might have been his band, which for this night included former Rollins Band bassist Andrew Weiss, that was the most impressive. Guitarist Ralph Spight added touches of warped fluidity as he unleashed sinewy coils of guitar noise as the perfect carpet for Jello’s yowling. “Clean As a Thistle” may have recalled the Dead Kennedys, but when Jello and the band launched into “California Uber Alles,” one could have mistaken them for the real thing in its day—even with Biafra’s upadating of the lyrics to include phrases about homeland security and Schwarzenegger. Indeed, even though much of the material from the group’s recent release proved to stand up to Biafra’s legacy, “Let’s Lynch the Landlord” and “Police Truck” were still the set’s visceral high points. This group proved to be the only one worthy of playing those songs these days. (Certainly the money-grubbing versions playing under the DK moniker aren’t.) By the time “Holiday in Cambodia” closed the first encore, Biafra had already dove into the crowd several times and nearly filled his quota for political comment. He could have closed the night on that highest of notes, as the second encore of mostly new material was some of the most heavy-handed of the evening in terms of lyrical content. Nonetheless, by this point Biafra had earned the right to do as he pleased, having already satiated the musical needs of anyone lucky enough to be there.

It was an evening of unrivaled musicianship at the Southern Theatre Monday night. After opener Robin Pecknold (of Fleet Foxes) mesmerized us all with his angelic voice, we waited almost an hour for Ms. Newsom to take the stage. It may well have been worth it.

The most obvious, but powerful, fact about seeing her in person is that she’s an amazing musician. She’s precise and passionate, and she doesn’t reach for those opulent notes—she nails them. And while she’s busy making all those uncanny sounds with her voice (and contorting her face to do so), she’s leading the band through her 10-minute masterworks and playing the 40-some strings of her harp. Somehow she manages to make it sound both otherworldly and earthly, ardent yet perfect.

The rhythm in Ms. Newsom’s performance was surprisingly prominent. Obviously the full-time drummer she had in tow had a lot to do with it. He made inventive use of of his instruments, including several tambourines, striking them and the cymbals with sticks, mallets, and his bare fists for unusual effects. And the other musicians (a pair of string players, a guitarist who also plucked a banjo and a mandolin, and a surprisingly versatile trombonist) added to the effect as well. But it was Joanna herself who brought the rhythm center-stage. She filled the syncopated spaces with head-nods and shoulder-shakes and emphasized the beat even more than usual with her phrasing. Primarily, though, it was her hands, as they crawled over the piano or undulated over the strings to pluck out those giant harp riffs.

The setlist was drawn mostly from Have One on Me, with occasional excursions back to The Milk-Eyed Mender. The opening notes of “The Book of Right-On” caused the crowd to erupt; it was the only notable crowd response of the evening. Her piano technique was on display for several songs, especially on “Inflammatory Writ,” in which her hands criss-crossed throughout the song. “Kingfisher” was the stand-out among the newer songs, building to the biggest climax in a night full of long songs with multiple climaxes. “Good Intentions Paving Company” and the opener “Occident” had the crowd bobbing and tapping along. The closer, “Emily,” the only piece from Ys, was truly epic and was so fiercely delivered that it held the crowd enraptured for its full 12-minutes. The set was brief (it was almost as long as the wait), but she delivered with conviction and spirit in every moment.