If you’re going to make strange music in Washington, D.C., this is the week to do it.

“Cakeblood,“ a composition-on-cassettes for 50 boomboxes, isn’t officially part of this year’s Sonic Circuits festival, but the  participatory work by local electro-indie-pop duo Bluebrain is certainly of a piece with the experimental music festival’s try-anything mission.

The skinny: Bring a boombox or some kind of tape-playing device to Dupont Circle tomorrow night at 7:30 p.m. (rain or shine, as of right now). There, Bluebrain—which is brothers Ryan and Hays Holladay, formerly of the  Brooklyn band The Epochs—will distribute as many as 50 cassette tapes containing about 30 distinct musical parts, and lead a procession of ad-hoc musicians around the city. There’s no way to ensure precise synchronization, which is hardly the point, anyway: The more chaotic, apparently, the better.

“It’ll sound like we’re in this weird, electronic jungle,” says Hays Holladay, 26, of the 30- to 35-minute work. “Sometimes it’s very eerie, and sometimes very pleasant. It has this sort of chirping kind of feeling.”

Hays says he and his brother have been working on “Cakeblood” since August, concocting the instrumental work from both analog and electronic sounds. “Ryan and I were playing around with [“Cakeblood”], and one of the boomboxes was dying, so it was at a slower pitch,” Hays says. “And it made it a different song. It was great.”

Hays acknowledges that “Cakeblood” is heavily inspired by the 1997 Flaming Lips album Zaireeka—which required playing four CDs at once. “We’re huge Flaming Lips fans, and, yeah, we definitely are copying their style on this one,” Hays says.  “It’s just one of those things that’s too cool not to do. It almost seems to transcend a work of art. It’s more about the experience.”

Ryan and Hays grew up in Northern Virginia, and returned to Washington after The Epochs went on amicable hiatus last year.  As Bluebrain, they’ve already released an EP, which is available on iTunes, and are set to drop their debut album, Soft Power, in early 2010.  The full-length shares the lushness of “Cakeblood,” if not the entropic experimentalism; like The Epochs’ records, though, it’s also decidedly poppy.

“We both play a little bit of everything, but not that well,” Hays says, laughing. “If we’re good at anything, it’s probably putting it all together.”

Bluebrain performs “Cakeblood” Thursday at 7:30 p.m. in Dupont Circle. RSVP at bluebrainmusic@gmail.com.