Mother’s Day, 1987. David Lang, Julia Wolfe, and Michael Gordon, three young composers fresh out of Yale, stage a 12-hour marathon of new music at a gallery on lower Broadway in New York City.

Double bassist Robert Black participates. “I had known Michael [Gordon] from another festival that I had been on,” he tells the Hartford Advocate from his office, cloistered deep below Millard Auditorium at The University of Hartford’s Hartt School of Music where he chairs the strings department. “So he called me up for the first marathon and said, I’d like you to come down and play Xenakis and this and that, and I’ll pay you 100 dollars, or something like that. Would you want to do it?”

Fine, Black answers.

Music from all over the place — and most of the composers who created it — mingles together. John Cage is there. So are Milton Babbitt, Steve Reich, and Pauline Oliveros. There’s beer in the back of the gallery.

“The very first marathon was very scrappy,” Black remembers. “Michael and David and Julia were calling up friends to come down and play. They were setting up the chairs themselves, you know, and I’m sure they used their own money to make it happen. We’d walk offstage and Michael would just reach in his pocket like at a rock club and hand out 100 dollars’ worth of 20s and say, ‘Thanks very much.’”

By most non-financial measures, the party is a huge success, and the Three Composers decide to do it again the following year. Word of mouth works its magic and the thing grows and grows. But they manage to maintain a healthy, eclectic mix of contemporary music: Carter, Cage, new music by the Three Composers, newer pieces influenced by vernacular pop and jazz, and so on. A formula and a brand name takes shape, and by the third year, presenters from other festivals appear, asking for Bang on a Can — as the marathon was known — to come to Europe.

The Three Composers think, How can we do this? Do we simply pick a repertoire, call players, as we have in the past, and ask them to go?

1992. Gordon, Wolfe, and Lang invite Black and a handful of other musicians familiar with the Bang on a Can repertoire to start a stable, avant-garde house band of sorts, which the Composers can then export to Europe or elsewhere as needed.

Black agrees, thinking the group would perform two concerts or three concerts the first year, seven the second year, back down to three the third year, then zero concerts the fourth year, when everyone becomes busy and nobody has time to write grants. You know, the usual trajectory for these kinds of things.

The newly autonomous All-Stars strike early gold, however, with a series of performances at the Walter Reed Theater at Lincoln Center two years later and a debut recording for Sony. Aware that the group has not been around very long, hasn’t played all the prerequisite small clubs, toured around in a van for a number of years, recorded on small labels, and so on, Black thinks, Wow, this has gotten pretty big, pretty fast. In 2004, Musical America awards them the title Ensemble of the Year.

December, 2010. Bang on a Can is an institution. The All-Stars is considered one of the pre-eminent avant-modern music ensembles of its time. There’s an office in New York with a small full-time staff and a number of dedicated interns at its disposal. The list of musicians they’ve worked with reads like an ultramodern bucket list: Philip Glass, Steve Reich, Brian Eno, Terry Riley, Meredith Monk, Ornette Coleman, Cecil Taylor, Thurston Moore and Lee Rinaldo, the Dirty Projectors’ David Longstreth, DJ Spooky.

After all this time — apart from one previous concert at Wesleyan — the All-Stars will play their first big area show on Dec. 9 at UHa as part of the Richard P. Garmany Chamber Music Series. For this, the series’ second full year, the Garmany Foundation substantially increased the amount of funds available, enabling Artistic Director Steve Metcalf, who is also the director of Instrumental Studies at Hartt, to engage the best artists in the world — literally. The Lincoln Center Chamber Society performed at Hartt on Oct. 14, and after the All-Stars the series continues with The Brentano String Quartet (Feb. 17) and the New York Woodwind Quintet (April 7). “We really are making a point to make it as varied and eclectic as we can,” says Metcalf. “It’s a real nice lineup, and this series, if I do say so myself, is a really important addition to Hartford’s musical life. Our series is all about trying to bring major, major artists to town, and it’s great that we have the chance to do that.”

The All-Stars plans to perform local composer James Sellars’ “Don’t Stop,” English composer Fred Frith’s “Snakes and Ladders,” Kate Moore’s “The Ridgeway,” four pieces for player piano by Conlon Nancarrow arranged by Ziporyn, three short pieces composed for the band by Longstreth, and Louis Andriessen’s Workers’ Union. For an encore, Black says, they might even pull out some pieces written for them by another Moore — Thurston.

The sextet occasionally pulls in actual pop/rock music and musicians. But it’s the group’s affinity with the whole aesthetic, the attitude and energy coming off the stage, that most closely links them to rock. Black says the members of the All-Stars grew up listening to and playing rock, jazz, garage rock, and electronic along with healthy doses of Bach, Beethoven and Brahms and were each deeply involved with musical worlds outside of the boundaries of classical music. Why keep all of those parts of their musical lives separate now? “That’s part of the whole appeal of the group,” Black says. “Even if a piece isn’t a ‘rock’ piece — it’s not written by Thurston Moore or something like that — it still comes from that idea. It informs everything we do.”

Still, Black says he never wants to find the sextet sitting around thinking, Hey, let’s find some sort of cutting-edge rock person to work with. “It’s more about listening to what people are doing in various areas and various fields,” he explains. “Who’s really interesting to us? Who is doing something really unique? We want to work with that person.”