The Los Angeles-based a cappella quintet Sonos has few rules, but those it abides by are ironclad. “We do our best to defy stereotypes,” says Jessica Freedman. “The whole approach has been to distance ourselves from kitsch,” chimes in Ben McLain. “And we don’t go ‘dow,’” adds Rachel Bearer. Dow? “That’s one of the words vocal groups use to emulate an instrument, like a guitar, with a made-up syllable,” Freedman explains. “We steer clear of that in arrangements.”

Read more about Sonos on Last.fm.