They just might be the quintessential Austin musicians.

Certainly they're some of the hardest working.

The four women of Tosca String Quartet — Leigh Mahoney, Tracy Seeger, Ames Asbell and Sara Nelson — are all regular members of the Austin Symphony Orchestra and some are also a part of the Austin Lyric Opera orchestra.

They've also toured with David Byrne and recorded with the Dixie Chicks. Among those they've gigged with are Arcade Fire, Spoon, Bonnie Raitt, Ian McLagan, Ray Benson and Vampire Weekend.

And they were featured on the soundtrack of and appeared in the film, "Waking Life," Richard Linklater's surreal, dreamy animated movie.

But come Saturday at the Scottish Rite Theatre, Tosca will perform the music that first brought them together way back in 1996: tango.

The women were just out of music school in the mid-1990s when they joined with veteran musician Glover Gill to form the seven-piece Tosca Tango Orchestra. That group became the center of Austin's then-nascent tango dance scene, playing regular gigs at downtown clubs.

The orchestra not only gave birth to the Tosca String Quartet, but it also led Gill to compose a catalog of original nuevo tango music, the modern jazz- and classical-influenced version of traditional tango dance music.

Gill's nuevo tango, in fact, makes up the entire soundtrack to "Waking Life."

Gill and Tosca Tango Orchestra recorded six CDs over the years including "Touch," a piece commissioned by Ballet Austin's Stephen Mills to accompany his full-length ballet of the same name.

"We've wanted to play this music again for years," says Nelson. "We still get emails from people all over the world asking when we'll play nuevo tango again, when we'll perform the music from ‘Waking Life.'"

For Saturday's show, the quartet will be joined by Gill on accordion, Chris Marsh on acoustic bass and Joshua Piper on piano. And yes, they'll play the edgy, moody tangos from "Waking Life."

In their first years together, the orchestra had as many as four to five regular weekly gigs at clubs in Austin and Houston, the Elephant Room and the Continental Club among them. That a band of classically trained string players were plying their trade in clubs and not just concert halls made Tosca unique at the time.

Now, Austin's percolating alt classical scene sees chamber ensembles playing in all manor of clubs, theaters, art spaces and other non-traditional venues.

"I think we really owe a lot (of our popularity) to Austin and to people being really open-minded here," says Asbell. "People weren't really all that surprised to see a (string quartet) playing in a bar."