Photo courtesy of Nonesuch Records When not hanging out in its serene, white room, Kronos likes to play music, such as "Sun Rings," a collaboration with composer Terry Riley and NASA scientists.

While we all know and love NASA for its spaceships and satellites and stuff, the organization has rarely been portrayed as a boon to the arts. But when it approached Kronos Quartet founder David Harrington about a collaboration, the violinist kept his ears open.

As it turns out, outer space generates some pretty interesting sounds. NASA had outfitted the Voyager shuttle with a special antenna designed to pick up ambient noise and thought some forward-thinking, well-respected musicians might be interested.

It's easy to see why NASA chose Kronos. The quartet is easily one of the most respected and well-known string quartets in the world, having played music from composers as diverse as Philip Glass, Igor Stravinsky and Jimi Hendrix.

WILL SEBERGER/Arizona Daily WilDcat Bruce Chamberlain, director of choral activities and music professor, directs the Arizona Choir yesterday afternoon in the Music building. Chamberlain also conducts the Kronos Quartet.

Kronos formed in 1973 when Harrington heard George Crumb's anti-Vietnam War composition "Black Angels." He decided he had to play it, and recruited violinist John Sherba, violist Hank Dutt and cellist Joan Jeanrenaud. Since then, Kronos has released almost 30 albums as an ensemble, played on soundtracks for several movies ÷ including "Requiem for a Dream" ÷ lost Jeanrenaud and gained cellist Jennifer Culp.

Its new piece, performed tomorrow at Centennial Hall, is entitled "Sun Rings" and was written by longtime Kronos collaborator Terry Riley.

"After hearing the sounds (from outer space), Terry seemed like a natural choice," said Harrington. "He deals with big themes, and this music certainly falls under that category."

But the immensity of space isn't the only big theme implicated in the piece. Riley began writing "Sun Rings" in 2001. After Sept. 11, however, work on the piece came to a halt.

"After Sept. 11, (Riley) just stopped writing," said Harrington. "He just couldn't do it. But he spent a long time thinking about it and realized it would have to change a lot. So he basically started over in December of 2001. After that, he told us the piece would require a fairly massive choir, so we had to think about how to do that as well."

Toting around a giant choir would have put a tour outside of Kronos' budget, so it decided to mine local talent. Bruce Chamberlain, professor of music and director of choral activities at the UA, was called in to direct students in the Arizona Choir for the performance.

"It's very challenging music, both for the quartet and for the choir," said Chamberlain. "There is multimedia, recorded sounds on a tape. That has to be coordinated with the live performers, and there's also projections that will go on the screen behind all of this. It's really a very fascinating piece."

Riley's music is typically difficult to perform, and "Sun Rings" is no exception.

"(The choral music) is not tonal, which means the piece is not in a key very often; so the pitch content is difficult for the choir," said Chamberlain. "It's written for a six-part choir rather than a four-part choir, so the texture is a lot more thick and dense. And the singers themselves only just have their music. They don't see on the page what the quartet is doing. The challenge for us has been finding the first pitch to come back in after we've been on a rest and the quartet has been playing."

Riley, a seminal minimalist composer, is known for sometimes composing music that's almost entirely rhythmic, such as his notorious and influential "In C" ÷ a 25-minute piece in which the only note played is C. The problems of writing around space sounds posed a particularly interesting problem.

"Terry found, while listening through the hundreds of hours of tapes from the Voyager, that there was no rhythm at all," said Harrington, "He likes to say, ÎThere is no rhythm in space.' So essentially, there is nothing natural about rhythm. It's all in the human mind."

Riley, though, found a way to adapt the sounds of outer space to his own style, making "rhythmic and complex" music out of an undifferentiated vacuum.

"It could have been a blockbuster affair," said Harrington, "But the music is extremely delicate and modest. For us, it's been a tremendous learning experience."

Kronos Quartet will perform with the Arizona Choir tomorrow at 8 pm.

Tickets range from $18-$40 general admission or $10-$21 for children and students.