Sless-Kitain sees the split as an amicable one, a matter of musical differences rather than personality clashes. "We were listening to a lot of, like, dub and a lot of Afro-beat. … We're all super into jazz, and Dan has a really sick jazz LP collection," he says. "And Dave wasn't feeling those influences much." Most of the songs on Say Speaker Speak were written when Brett was in the band, but several months of rewriting made the songs lusher and more melodic. "There was a long period, I think, where we reworked all these songs," Edwards says. "And then I think there was a pretty long period where we wrote like one song, I swear." She's a subtle singer, and while her dreamy delivery enriches the songs, "Deep Black Design" and "Say Speaker Speak" would be just as hypnotic without it. It's hard to imagine Brett in such soft sonic beds, but Edwards was still working out her parts when the band was in the studio with Jeff Zeigler late in 2004. Lyrics and vocal melodies had been a more collaborative effort before, but the switch to a woman's voice threw the guys for a loop.

Brett's departure wasn't the first personnel shift in the group's evolution. Snyder and Edwards, who knew each other from growing up in Allentown, reconnected in Philly and tried a few different approaches before clicking with drummer John Nigro. On other nights, Snyder made music with Ziprin and Brett, whom he'd met at a party. The original South Congress lineup came together when Snyder melded the two trios into a quintet. Brett wasn't into the idea of keyboards at first, but he changed his mind once he heard Edwards. The five-piece started jamming, but with Nigro always out of town, Joe Boyle stepped in. Cordalene kept Boyle busy, though, and the nameless ensemble was once again down a drummer.

Enter Ziprin's Temple Law pal Cynthia G. Mason, who acted as matchmaker. "I was walking home one day and called Cynthia to just have a drink, and was telling her, 'If you run into any drummers, let me know,'" Ziprin recalls. "And she was like, 'Well, I'm going out with my friend Areif tonight.'" Sless-Kitain, who'd come up with the singer-songwriter in Lower Merion High School's music scene, had recently moved back to the area from Washington, D.C., where he'd played with Bluetip and Regulator Watts. Mason hooked up Sless-Kitain and Ziprin at that night's Need New Body show, and within a few months, South Congress was playing to paying crowds. But over the next year and a half, the instrumentalists found themselves pulling in a less traditionally indie-rock progression than their singer.

Which isn't to say they knew exactly what they'd do without him. Saxophonist Ian Fraser filled in some of the spaces for a few shows, but everything started falling in place once Edwards stepped up to sing. "It was something that I always kind of wanted to do but just didn't have the confidence," she says.

Brett's departure was also an excuse to ditch the South Congress moniker, which no one really liked. For Ziprin, who grew up in Texas, having a band named after Austin's scenester strip bordered on embarrassing. "It's like being from Philly and naming your band South Street," Snyder explains. For their relaunch, the quartet nicked a name that Snyder came across in Benjamin Franklin's autobiography. "I've never read his poetry," Snyder says of the historical Aquila Rose. "I think more phonetically we liked it."

That reasoning suits a group that knits songs together out of improvisations. "We're not the type of band where someone brings in chord changes and writes a song," Sless-Kitain says. "It's more like we jam out loud."

The songs come faster and more deliberately now, but speed is a relative concept. "Some bands will write 30 songs in a year," Snyder says. "We'll write eight, seven." Everyone's got other commitments — Snyder's with The Jai-Alai Savant, Edwards is in Relay, and Ziprin and Sless-Kitain back Janet Kim in Evil Janet — but they still make time to improv. They record every practice, but they're not too worried about organizing their tapes or losing work whenever Snyder's basement floods. They haven't set a timetable for going back into the studio, preferring to dive deeper into the songs on Say Speaker Speak. And at the same time, they're looking for wider distribution for the self-released album. "We really want to get that record to do some work for us," Ziprin says. "We've done a lot of work for it."