The double album marks a turning point for a band. Sometimes it’s a sprawling odyssey that establishes a band as both ambitious and important; sometimes it’s a long-winded mess that gets relegated to the dustbin of pop culture.

Folk trio Maggi, Pierce and E.J. are about to release their triple album, “Silver.” Three whole discs of their quirky, melodic, jazz-inflected acoustic rock. That’s an awful lot of music. Can the Philadelphia-based indie folksters live up to the huge expectations they’ve made for themselves?

All multi-instrumentalists, the self-described “common-law siblings” have made Maine a kind of second home when they’re on the road, playing across the state many times a summer. They’re itching to get “Silver,” their sixth album, out to fans, and this Saturday they’re playing one of their biggest Maine shows ever, a CD release party at the Gates Auditorium at Bar Harbor’s College of the Atlantic.

The sweet, sprightly Maggi described the three discs of “Silver” as a reflection of different parts of a typical day.

“The first disc, Morgen [Morning], is thoughtful, melancholy, mellow. Disc two, Mittag [Noon], is a bit more upbeat, let loose, feel good, shake your bum,” she said. “Disc three, Nacht [Night, naturally], rocks out and is raw from the gut.”

Reviewers have name-checked bands from multiple musical genres when trying to describe M,P and E’s sound. What would a band compared to the Barenaked Ladies, Jeff Buckley, Joni Mitchell, the Pixies and the Squirrel Nut Zippers sound like?

Apparently, like Maggi, Pierce and E.J.

Maggi said she personally had been listening to everything from Audioslave to bluegrass, though the band was immersed in German music while recording “Silver” in a studio in Berlin.

“What I love about the [multiple-disc format] is that it’s a bit like listening to a vinyl record,” she said. “You put on one side, and when it’s over, you can flip it and listen to side two, or you can just think about it for a little while. I like to think about music and let it sink in.

“Also, I’m a sucker for silvery glittery things, and our album is sparkly and looks really cool,” she said, referring to the eye-catching silver glitter cover art for “Silver.”

Live, the trio is upbeat and all over the map stylistically. They’ve been rumored to cover Yoko Ono songs, and even bust out a metal riff here and there. And they have some of the prettiest three-part harmonies this side of Crosby, Stills and Nash. It’s a sweet summer treat, and those in Bar Harbor Saturday will be the first ones to get a chance to pick up a copy of “Silver.”

Maggi, Pierce and E.J. will play at 7:30 p.m. Saturday, July 30, at the Gates Auditorium in Bar Harbor. Admission is free. For more information, visit www.mpeband.com.

Emily Burnham may be reached at eburnham@bangordailynews.net.