Fitz and the Tantrums’ retro-soul rhythm made it hard for the packed crowd to keep still Wednesday night at the El Rey.

You had to wonder if the threat of public ridicule was necessary Wednesday night at the El Rey Theatre, where Michael Fitzpatrick of Fitz and the Tantrums assured the capacity crowd that he’d point out anyone he saw not dancing to his song “MoneyGrabber.” That tune came at the very end of this L.A.-based retro-soul outfit’s 80-minute concert; nearly an hour earlier, the audience had already demonstrated its allegiance by cheering a flute solo before knowing whether the solo was any good. Still, Fitzpatrick’s warning produced results: In a decent-sized room packed with typically reserved hipsters, not one appeared worthy of being shamed.

It’s been a speedy ride to such devotion for Fitz and the Tantrums, who played their first show less than two years ago and whose debut album, “Pickin’ Up the Pieces,” came out in August. Some of the band’s success can be attributed to the pop climate: In New York, Sharon Jones and the Dap-Kings have magnetized the soul-revival sound for a generation too young to have experienced the real deal; other acts, including Eli “Paperboy” Reed and L.A.’s Mayer Hawthorne, have increased the heat. And there’s no discounting the role “Mad Men” has played in galvanizing interest in the sort of group that turns up onstage wearing crisp two-tone suits — as Fitz and the Tantrums did Wednesday.

When it comes to evoking the products of a past musical era, there’s a thin line between love and hokiness. Too many retro-soul practitioners slip into mannerisms that range from cartoonish imitation to flat-out minstrelsy. This Silver Lake-based sextet makes brash ’60s-style pop that clearly derives from artists like the Temptations, but singer-bandleader Michael Fitzpatrick brings his own punky attitude into the room and makes the sound fresh.

The band’s debut LP, recorded in former studio engineer Fitzpatrick’s living room, rides heavily on the sound of vintage organ and crisp drums. Unusual instrumentation — the band doesn’t have a guitar, but does prominently feature sax — leaves much room for aggressive vocalizing, which reaches its highest pitch when Fitzpatrick plays against his more-than-able co-vocalist Noelle Scaggs. There’s a certain sameness to the songs’ tempos and arrangements here, but in general the hooks catch and the energy feels genuine. Fitz & the Tantrums is the kind of band that communicates best in concert, but this album serves as a fine proxy and party-starter.

—Ann Powers

Fitz & the Tantrums
"Pickin’ Up the Pieces"
(Dangerbird Records)
Three stars (Out of four)