For about two decades now, the Muir String Quartet and composer Joan Tower have collaborated closely during their annual three-week residency in the Park City/Deer Valley area. During this time, the quartet has performed a number of Tower's works, often with the composer herself at the piano.

For their concert next week, the Muir will give the local premiere of Tower's most recent work: "Piano Trio: For Daniel."

Written for the Kalichstein-Laredo-Robinson Trio, the work received its first performance last March in Tucson under the auspices of the Tucson Chamber Music Society. The group also played it once in New York City. This will be the work's third performance.

According to Michael Reynolds, the Muir's cellist, the trio still isn't in its final form. "It's still in the process of creation. Just the other day, (Joan) e-mailed me with a bunch of changes for my part."

Tower said that making changes in her scores, even after a work has been performed, is not unusual. In that way, she can be sure the work in question is to her satisfaction before sending it to her publisher.

"I wait a couple of years before submitting (a work) to my publisher," Tower said. "Otherwise, you live with your horrible decisions. Once it's sent to your publisher, it goes into cement."

She dedicated "Piano Trio: For Daniel" to her nephew Daniel, who passed away last December at age 48 after a long battle with a debilitating genetic illness. "It's very sad," she said. "He was an athlete, but by the end he had to have an oxygen tank to go on the golf course."

Tower's wish was that her nephew could hear a performance of the trio. "I was hoping he would be able to hear it, but he didn't. It's sad, because he had a daughter who also grew up with this disease."

"Piano Trio: For Daniel" will be played by Reynolds and Peter Zazofsky, the Muir's first violinist. Tower will be at the piano. "It's the most difficult thing I've played in a long time," she said.

Even though she's still fairly active as a pianist, Tower said she tries to play works that aren't challenging. "I play slow pieces, things that are not too demanding."

Tower was a founding member of the Da Capo Players in 1970, an ensemble that is still in the forefront in promoting contemporary music. Today, she limits her playing to her own music. "I play 'Big Sky,' 'Tres Lent' and 'Petroushskates,' which is pretty fast but not that difficult."