DC9 hosted Tanlines, a Brooklyn-based indie rock duo, at a sold-out show on Wednesday. (Marlon Correa/The Washington Post)

An advantage to seeing a band tour in support of its debut album is catching it on a small stage. And Tanlines, the New York-based duo of Jesse Cohen and Eric Emm, is touring behind a very special debut. “Mixed Emotions” is one of the year’s best, an immaculately constructed, paced and sounding album that nestles in a warm, synthy spot between ’80s new romantic and modern electro-pop. The songs radiate a familiar, comforting and undeniable glow.

The duo’s performance at a sold-out and tightly packed DC9 on Wednesday night was certainly intimate and plenty of fun. But by the end you wished Tanlines could fast-forward through its infancy and get to the point where it is playing late-night slots at outdoor festivals instead of small, kind-of-smelly clubs. These songs are made for big spaces and bigger sound systems.

The warm washes and tribal, rhythmic pulsing of “Brothers” and “Lost Somewhere” are sounds that should be enveloping. On Wednesday they felt partially deflected. Tanlines’ best song is “All of Me,” which has a chorus surge so massive and perfect that you could imagine it filling a giant venue. Instead, concertgoers jumped into the air waving their outstretched arms a bit tentatively, perhaps worried they might smash their fingers on the club’s low ceilings.

The other reason a bigger venue would suit Tanlines best is that there’s simply not much happening onstage. There was little need to get an up-close view. Cohen (a Potomac native) banged around on various percussive bits — a cymbal, a floor tom, some congas — and pressed on keyboards. Emm strummed a guitar, crooned and pulled off his slightly disheveled, rock-star-in-a-jean-jacket look with ease. Early D.C. adopters of Tanlines got a nice gig to remember, but the real payoff will be when more people join the party and make that party bigger.