Composers going on and on in all different directions

Bang on a Can, the New York circle of composers whose trademark 10-hour marathon debuts at the Live Arts Festival on Sunday, maintains the right to go to extremes.

All of them.

Some moments might be extremely pretty. Others enter less-explainable extremities such as the extraterrestrial Sun Ra Arkestra, the often-ethereal So Percussion, indie rock band Normal Love, Asphalt Orchestra playing Frank Zappa, and the marathon's house band, Bang on a Can All Stars. Hosting the event at World Cafe Live are the three increasingly eminent composers who founded the marathon in 1987, Julia Wolfe, Michael Gordon, and David Lang.

"Philadelphia is such a beautiful old historic city that, in a way, it's more radical to bring this into that environment," says Wolfe, who grew up in nearby Montgomeryville.

At least Philadelphia has fewer outside distractions than New York over the 2 p.m.-to-midnight duration. "We try to make it difficult for people to leave," said Kenny Savelson, executive director of Bang on a Can.

Does he hide the audience's shoes?

"We try to be as entertaining as possible," he assures. He also minimizes information about the individual artists so the audience can't prioritize.

Staying for the whole thing is a point of honor in some circles, an act of immersion for others, and a defiance of practicality for all - particularly those producing the event. Sets range in length from 12 minutes to an hour, meaning that 100 or so musicians will be trooping in and out of the cozy World Cafe Live, along with sound and stage staff. To give everyone a sound check, Live Arts bought out World Cafe for the night before, which happened to be an expensive Saturday. The production price tag is $125,000 - high for the Live Arts Festival, but reasonable considering that some of New York's and Philadelphia's best new-music groups will be present.

"We've mostly been oriented around dance and theater," said Nick Stuccio, the Live Arts Festival's producing director. "All of the work over the years has had some music component, there's been a concert here and there, but we've been remiss. ... "