From left, Flasher band members Emma Baker, Taylor Mulitz and Daniel Saperstein. (Jared Soares for The Washington Post)

It’s partly the more layered production and partly the less-confessional songs, but Flasher’s impressive debut album, “Constant Image,” dials back the urgency of the self-titled EP that preceded it. Saturday night at the sold-out Black Cat backstage, however, the distinction between new and old was less pronounced.

The local trio began at a gallop and barely slowed throughout the 45-minute set, save for a broken bass string and a bit of banter with the hometown crowd. Such “Constant Image” tunes as “Who’s Got Time?” and “Skim Milk” pulsed and surged just like earlier tunes “Destroy” and the show’s climactic encore, “Erase Myself.”

Flasher’s style could be termed maximal minimalism. “Constant Image” includes keyboard and horn touches, but onstage the band musters only guitar, bass and drums. Unlike in most rock power trios, though, all three musicians sing, and in a variety of modes. Guitarist Taylor Mulitz, bassist Daniel Saperstein and drummer Emma Baker may chant in unison, employ folk-rock high harmonies or engage in vocal counterpoint that’s as intricate and quickly shifting as the instrumental interplay. The means are modest, and the tunes range from short to very short, yet the music is far from simple.

Although the band members do an admirable job of synthesizing their influences, their style is planted solidly in the post-punk that germinated in the late 1970s and bloomed a few years later. Most of the songs rush and roar in the manner of the Feelies and the Smiths, while guitar and bass parry in the way punk learned from funk. Mulitz’s guitar drenches many passages with jangle but sometimes shifts to trebly jabs or drops out altogether. The melodies can often be sweet, but the overall vibe is, as one song title puts it, “Tense.”

That may be merely a stylistic preference, or reflect the musicians’ fundamental unease. Some of the lyrics suggest the latter, but in performance the words melded with the instruments and became pure sound. Fidgety as some elements were, the overall effect sounded a lot like joy.

Preceding Flasher was Dehd, a Chicago trio whose musical similarities with the headliner included interlaced male-female vocals and quick, punchy songs. The two groups have a personal affinity as well, as the members of Flasher demonstrated by joining Dehd to add thump and clamor to the supporting act’s uncharacteristically caterwauling final number.