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.” With a cappella vocal groups proliferating madly on college campuses and infiltrating the mainstream via TV shows like Glee, Sonos couldn’t have emerged at a more propitious time. But the three women (Freedman, Bearer and Katharine Hoye) and three men (McLain, Chris Harrison and Paul Peglar) who produce its tapestry of tones are swimming against the tide of jukebox set lists, doo-wop inflections and collegiate shtick in their quest to take a cappella music to a new, more sensual, more musically adventurous destination. They’ve already won plaudits from such tastemakers as Chris Douridas of L.A. bellwether station KCRW-FM, who praised Sonos’ “innovative vocal arrangements” and “inspired repertoire, supremely delivered.” “Prepare to be stunned,” advised the U.K. newspaper The Guardian, while Campus Circle lauded their “unaccompanied magnificence.” Beyond admiring the group’s sonic achievements, critics also noted its “sexual tension” (L.A. tastemaker outlet The Deli Magazine) and “sex appeal” (Pasadena Weekly). On its debut album, SonoSings, the group combines a rich, classically choral sensibility with an ultra-modern repertoire and sonic toolkit. The result is a spellbinding fusion of ancient and contemporary sounds, as songs by the likes of Radiohead (“Everything in Its Right Place”), Sara Bareilles (an a cappella veteran herself, she joins Sonos for a rendition of her “Gravity”), Fleet Foxes (“White Winter Hymnal”), Bon Iver (“Stacks”), Rufus Wainwright (“Oh What a World”), Björk (“Joga”), Imogen Heap (“Come Here Boy”) and other cutting-edge creators are transformed into mesmerizing vehicles for voices only. The only pre-existing pop megahit in the batch is “I Want You Back,” but the group’s moody, trip-hop rendition radically re-imagines the tune – bringing out the dark, despairing lyrics that were all but negated by the Jackson 5’s bouncy, bubblegum original. With the passing of Michael Jackson, the version serves as an emotional homage. Harrison produced and mixed the disc (with Gabriel Mann and manager Hugo Vereker, who assembled the group, provided A&R direction on the album and dreamed up the stark reworking of “I Want You Back”); he also handled several arrangements. “Chris is a freakin’ genius arranger,” enthuses Freedman, “but we all have experience arranging and writing music, and we bring so many diverse backgrounds to the table that we’re greater than the sum of our parts.” Indeed, Freedman, Bearer and Hoye all contributed sterling arrangements to SonoSings. Agrees McLain, “If any of us weren’t what we are, Sonos wouldn’t be Sonos.” Performing “I Want You Back” and other songs live, Sonos further pushes the envelope with the judicious use of effects pedals, guided by resident “gearhead” Harrison. McLain, in addition to singing leads and harmonies, contributes beatboxing that’s looped into a panoply of polyrhythms. (He developed the latter skill while lying in bed in his small-town California home, listening to hip-hop station KMEL-FM; his first cassette, he volunteers, was Very Necessary by Salt-N-Pepa.) But that’s just the tip of the technological iceberg. “We’re very comfortable performing purely acoustically,” explains England-born, L.A.-bred Hoye, who attended the famed Berklee School of Music before heading to UCLA, where she met her future co-harmonizers. “But in the studio and playing live with a sound system, we essentially make electronic vocal music. We think of our collection of pedals and loops as the seventh member of the group.” “When we sing ‘I Want You Back,’ I use an octave pedal,” she adds, referring to a device that splits notes played or sung into two tones an octave apart. “That way, I get to fulfill my fantasy, as an alto, of singing bass. You can hear a bass part, but I’m the only one singing. It confuses people.” That said, the electronics are a small part of the picture – the Sonos experience is first and foremost about how “You can go from nothing to something just by opening your mouth,” as Cleveland-born Cali transplant Peglar – whose stratospheric range is variously described as “rock tenor” and “ballsy falsetto” by his compatriots, and who’s been spotted playing keyboards on the aforementioned TV series Glee – puts it. Like almost everything else about the group, its origin and development have been unconventional. “We sort of became a band backwards,” explains elder statesman Harrison. “We formed, rehearsed, made a record and then started performing live.” The San Diego native – who grew up watching his dad playing in bluegrass bands – sang in the famed UCLA vocal ensemble known as Awaken A Cappella with Bareilles and fellow future Sonos members Freedman (who comes from Santa Rosa, Calif.) and Peglar. The latter two had attended high school in Santa Rosa with McLain. Bearer – who grew up singing opera in Tulsa, Okla. (“the buckle of the Bible Belt”) – had been kept from pop music by her musical-purist parents, but says singing a cappella changed her life completely. She attended both UCLA and USC, and was a member of celebrated a cappella ensemble SoCal Vocals when she met Harrison, who invited her to audition for the group; after a mere five rehearsals, she flew to New York for a performance. Rather than bang out the record over a few months, Sonos took its sweet time. “We recorded the Radiohead track nearly three years ago, and we added two new tracks the day before it was mastered,” Freedman reveals. “It spans our entire evolution as a group. We’ve really grown into our own sound and style.” They performed their first gig at the Santa Rosa high school Freedman, McLain and Peglar had attended together. While their vocal mix clearly delighted the crowd, Peglar recalls, their visual presentation hadn’t yet evolved. “I watched a video of it and promptly deleted it,” he relates, “because it was not what we wanted to present to people.” Some seven months passed before their next show, however, and the group soon developed its signature presentational style – sleek, sexy and confrontational, with an air of mystery not often found in the a cappella world. Perhaps the ensemble’s most revelatory live moment thus far came in the gorgeously austere confines of a 17th Century London church, where they sang for an audience of fans, friends and industry folk. Performing “White Winter Hymnal” and “Gravity,” particularly, in such a setting, Peglar remembers, “Was kind of a checkpoint, because it was the six of us and the audience, with nothing in the way. I’d never even been overseas, so just being in London was amazing; compounding that was making music with my friends in this incredible church.” “There’s something organic and mysterious about singing a cappella,” Peglar continues. “It’s beautiful and intangible. It could’ve been centuries earlier with a piece of classical music, but we’re taking something from last year and making it just as haunting and interesting. I think that’s what’s most captivating about us.” Manager Vereker reports that the music-business types in attendance were stunned. “Almost every one of them came up to me afterward,” he says, “and told me they’d never seen anything like it in their lives.” With its debut album complete at last, the group is prepared to bring its one-of-a-kind vocal blend to the world – and plans to pepper its tour schedule with venues like performing-arts centers, colleges and even living rooms. But whether they’re in a courtyard, a club or a concert hall, Sonos will always seek that intangible, mysterious, intimate fusion of timeless tones and modern meaning – with nary a “dow” to be heard. Sonos performed on Season 3 of the NBC show "The Sing-Off" and they were eliminated in the 4th episode.