Q: What blends four impassioned voices in subtle interplay, risking fractious outbursts in a no-holds-barred, tag-team whirl?

If you guessed "the model family" or "the Middle East’s current stewards," you’re not wrong, but as this is a music column, quiz winners picked "the string quartet." The quartet is chamber music’s concentrated triumph from Haydn to Elliott Carter, with its adherents extolling the form for its intimate but lively dialogue among interdependent instruments. Today’s high-profile practitioners have parlayed its inherently creative nature into projects like affordable, one-day performances of Bartók’s six quartets by the Emerson String Quartet and the planet-wide commissioning spree that’s made the Kronos Quartet a world music juggernaut.

And now comes Ethel, whose self-titled debut on Cantaloupe Music is out in October. The timing is perfect, as the group has spent recent years grafting the classical string quartet model to its logical, late-twentieth-century extensions: the hard-bop quartet and the rock band.

Much on the scene since their first gig at Context Studios almost five years ago, Ethel did an early summer performance/ installation at the midtown Whitney that they called "In the House of Ethel," and a three-part series early this year for director George Steel at Columbia’s Miller Theater. In the Miller series, they indulged their fondness for living composers, covering the complete quartets of John Zorn and Julia Wolfe and then filling bills with composers they’ve programmed on their CD.

Ethel’s members share musical seasoning of impeccable authority and revealing diversity. Cellist Dorothy Lawson has played with the New York Philharmonic and Orpheus Chamber Orchestra, while violist Ralph Farris was in Orpheus and in the musicals A Chorus Line and The Lion King. Farris was Roger Daltrey’s musical director, and his rock world experience is mirrored by violinist Mary Rowell’s tours with Sheryl Crow, Joe Jackson, and her own band, the Silos.

Rowell has soloed with symphony orchestras in Houston and Warsaw. Her fellow violinist and Ethel’s co-founder, Todd Reynolds, studied with Jascha Heifetz and revived the dancing fiddler in Annie Get Your Gun. He brings avant-garde credentials from Steve Reich’s group and downtown’s Bang on a Can, cutting-edge experience reinforced by Lawson’s stint playing for Baryshnikov’s White Oak Dance Project.

Mary Rowell calls Ethel "an amazing group of people. We have warts just like everybody else, but when we get on stage and go, there’s this power, it’s kind of out of your control. If you’ve ever been on a wonderful horse, there’s that power: The horse and you are one, and you can’t do anything wrong, and you go over all the jumps. Or riding along on a motorcycle and you get those S-curves coming up and you just fly through them. It’s an incredible feeling; it’s like driving a Ferrari."

Ethel, the CD, plays with crisp austerity, each instrument tinged with its own fibrous resonance and established within a startling spatial presence. Composer Phil Kline’s "The Blue Room" is a telling exploration, four five-minute pieces that move from the spare, suspended, insistent "The River" to a motoric, Glassian "March." The faint title piece, a violin-led, melancholic helix, sets up "Tarantella," where accelerating segments evoke the southern Italian antidote for dance frenzies that result from a tarantula’s bite.

Kline’s suite is preceded by John King’s three-part "Sweet Hardwood" and followed by violinist Reynolds’ contribution, "Uh…It All Happened So Quickly." Reynolds’s piece bursts into play with Lawson’s deep, alert cello, then sways from hoe-down arcs to a quartet passage as quicksilver and articulate as peaks found in Janacek’s or Ligeti’s work.

Everything clocks in in the 4:30-to-6-minute zone until Ethel’s concluding nine-minute lilt with composer/bass clarinetist Evan Ziporyn. And, at under an hour, the CD invites repeat listening rather than pushing for an exhaustive account of current quartet compositions.

Upcoming gigs at the Library of Congress and Philadelphia’s new Kimmel Center will broaden the band’s national base, and they’ll play Zorn’s quartets in Venice at the invitation of Biennale musical director Uri Caine. Todd Reynolds, a veteran of Caine bands, told Caine of Ethel’s Miller Theater series when the two were in Palermo, where Reynolds was conducting a seventy-player/seventy-singer opera.

Such fortuitous agreements are paving Ethel’s future— just as they formed the band’s origins. "John King had asked Mary to put together a band," Reynolds relates of Ethel’s beginnings, "to play his music for a project at the Kitchen. I wasn’t able to do that gig, but at the same time, [baritone and contemporary music mainstay] Tom Buckner asked me to put together a band to record a piece. A friend said ‘If you want to play in a string quartet you want it to be the people you’d die to play with.’ That was simple for me: Mary, Ralph, and Dorothy."

"That thing of Buckner’s was the first opportunity to do that," the violinist continues. "I produced more concerts for the band, and Mary, being the tremendous freelance player that she is in New York, collaborated, and we’d share gigs. It became clear after about a year that it was time to regroup and think of things as a complete democratic collective. And [that’s when] Ethel started as a band."

The name came from an early Romeo flame in the film Shakespeare in Love, though volatile refinery liquids were more obvious associations at their early-August, standing-room gig at Joe’s Pub. Ethel was chummy from the Pub’s compact stage, and deft and honed in a set that included "The Blue Room" and one of King’s propulsive blues. They were also amped, with Lawson’s cello figures as evocative as Yo-Yo Ma and as compulsive, at times, as Sonic Youth bassist Kim Gordon.

The Pub’s director, Bill Bragin, recalls first hearing Ethel when they were backing singer Dayna Kurtz. "It was a really visceral response. They came off the stage and I immediately went back and said ‘We need to find a date for you.’" He admires what he terms "their commitment to a new repertoire. They way they’re championing their composer/peers is really important."

Bragin nominated Ethel for Arts International’s coveted DNA Project grants, funded by the Mellon Foundation. Their recent DNA award helps get them to Venice, where a documentary team will be filming their Zorn concert. Renata Petroni of A.I. feels that Ethel is "making the right moves. There’s a big buzz around them, and if they continue to be good and make good selections of music and continue to play as well as they do…"

We’ll leave the rest for future quizzes.

Track Ethel’s activities at www.ethelcentral.com, and CD availability at www.cantaloupemusic.com.