Jeff Apruzzese is one of four members of a one-man band.

Well, maybe that’s not a completely fair statement. But the hot indie-pop band Passion Pit has a fairly unconventional structure to be sure, with frontman Michael Angelakos writing and recording all the songs by himself and the other members joining him live.

But they’re not hired session players — they’re all part of the band. They’re just not part of the recordings.

So far, the formula has worked pretty well. Passion Pit appeared on NBC’s “Saturday Night Live” in October, and one of its recent singles, “Take a Walk,” is not only getting radio airplay, it’s been used in TV ads for Taco Bell.

The band’s latest album — “Gossamer,” released last summer — went to No. 4 on the Billboard 200 album chart, and the song “Where I Come From” was the lead track on the soundtrack for the teen vampire blockbuster “The Twilight Saga — Breaking Dawn, Part 2.”

So Apruzzese isn’t complaining about the unique band arrangement.

“The whole project has always been Michael’s ideas. It’s never been a collaborative process in the studio,” said Apruzzese, 27. “In a live setting, the songs change; that’s when our process comes together. The longer we’ve played together, the more we talk about going into the studio and working on something together.”

The songs that have gotten a lot of airplay are sort of retro but definitely upbeat. “Take a Walk” features vocals that sound a little like mid-’70s Electric Light Orchestra. “Carried Away” has a slight disco feel, yet feels contemporary at the same time.

Passion Pit’s formula has worked so well that the band is booked for two shows at Portland’s State Theatre, which has a capacity of more than 1,800. Tuesday’s show is sold out, but tickets for Wednesday’s show were still available at press time.

The members of Passion Pit — Angelakos (lead vocals and keyboards), Apruzzese (bass), Ian Hultquist (keyboards and guitar) and Nate Donmoyer (drums) met around 2007 while attending college in Boston. The band name came from a slang term for drive-in movies — because of all the teenagers smooching in their cars.

The band released an EP, “Chunk of Change,” in 2008, which reached No. 35 on Billboard’s Heatseekers chart. A full-length LP, “Manners,” quickly followed in 2009, and went to No. 51.

With the release of “Gossamer,” the band was thrust into the big time — quickly. Passion Pit had to cancel some shows last July so that Angelakos could be treated for bipolar disorder, which he has been battling since his teen years. But by August, the band was performing again.

After near-constant touring, Apruzzese said that right now, when he’s at his home in Brooklyn, N.Y., he’s “a total hermit,” cooking and reading a lot.

A highlight of the band’s success so far has definitely been being on “Saturday Night Live,” said Apruzzese. He said cast members Bill Hader and Fred Armisen “went out of their way” to make the band feel welcome.

As is often the case with pop acts getting hot, things like TV appearances happen quickly. Apruzzese said the band was on tour in Australia earlier in the fall when they got the call that “SNL” wanted them — in two weeks.

“We flew home and had about two days to rest and do rehearsals,” said Apruzzese. “But we all grew up watching that show, waiting to see which bands would be on, so we were psyched.

“It turned out to be an awesome experience. It went by in a blur.”

Staff Writer Ray Routhier can be contacted at 791-6454 or at:

rrouthier@pressherald.com