Musicians are becoming increasingly agitated by the plague of ringing cell phones and beeping watches in the concert hall, but composer Gavin Bryars takes a more zen-like view of the uninvited chirps, beeps, and squawks. Having once endured the humiliation of having his own phone ring (with a tone he himself had composed) during a performance of his own music, Bryars has come to accept the unscheduled interruptions as nothing more than spontaneous extensions of the concertgoing experience, and sometimes, as legitimate musical enhancements.