Cell phones take center stage.

Scores of cell phones twittered, beeped, and burbled all at once inside a concert hall in River Forest, Ill., on October 1. But the composer was delighted, and the orchestra--the Chicago Sinfonietta--continued playing the world premiere of the Concertino for Cellular Phones and Symphony Orchestra by David N. Baker, a music professor at Indiana University. Paul Freeman, the group's conductor, told the audience beforehand: "This is a great moment in history, when we can say to you, 'Ladies and gentlemen, turn on your cell phones.'" A device similar to a traffic light signaled audience members to activate their rings at various points in the piece. Four players onstage used amplified cell phones programmed with classical themes and random rings. Audience participation was key. "It was a way of giving people control, at a concert," says Baker. "I'm hoping people will see the comedic element, but more importantly, that maybe you can have fun at a symphony concert."