Jonathan Rado and Sam France of Foxygen perform at the Rock N Roll Hotel in Washington. (Kyle Gustafson/FOR THE WASHINGTON POST)

Foxygen isn’t the kind of band that plays a lot of covers. Why would it? The L.A. group’s songs are cobbled together from such a recognizable cadre of ’60s and ’70s rock-and-roll styles that it’s a wild understatement to say the band members wear their influences on their sleeve.

At a sold-out Rock & Roll Hotel on Wednesday night, the core Foxygen duo of Jonathan Rado (guitar/keyboards) and vocalist Sam France — augmented by an un-introduced bassist, singer and drummer — played a 45-minute set that flirted at times with complete disintegration. And while France’s occasionally wince-inducing stage antics evoked images of a bad high school party, the music was delivered with exuberance, crashing forward with the gusto of a band climbing onstage for the first time. That enthusiasm more than made up for the often-sloppy interpretation of the band’s songs.

France and Rado, both 22, have been writing, recording and self-releasing music since 2005, but it was only with this year’s critically acclaimed “We Are the 21st Century Ambassadors of Peace & Magic” that the pair’s creations have reached a wider audience.

Produced by the inventive musician and artist Richard Swift, the songs drip with psychedelia and deja vu: Here they snatch up the chorus of Elvis’s “Suspicious Minds,” there they pull a garage-rock riff from the Sonics and duct tape it to the Stones’ “Get Off My Cloud.” As pundits have pointed out, the contemporary influence of artists like Ariel Pink and the Brian Jonestown Massacre are audible, but Foxygen pulls something sparkling out of the mess more often than not, often through sheer determination. That spirit saw it through on Wednesday, as the band worked the middle slot on a bill headlined by Unknown Mortal Orchestra and opened by Portland’s Wampire.

It was clear from the opening “Make It Known” that things were going to be messy. Rado’s spiraling guitar combined with France’s deeply echo-laden vocals to render the rhythm section nearly inaudible. The song’s first tempo shift was so drastic it kind of hurt. But when all five of the members’ voices swelled together on the chorus, the joyful upsurge was inspiring and soothing.

And so it went, through “Shuggie,” “In the Darkness” and “San Francisco”: Foxygen lost focus, regained it, jumped around awkwardly and shifted tempos starkly. While anyone encountering the band for the first could have easily written it off as an unholy mess, those already entranced by Foxygen’s recordings — and there were plenty in attendance — likely found just enough evidence to believe that France and Rado will eventually be able to add things like tight arrangements and a balanced live sound to their boundless enthusiasm.

Foster is a freelance writer.