From the press:

It's the dreaded sound at any live performance – a ringing cellphone. That's what happened Tuesday night at Lincoln Center's Avery Fisher Hall toward the end of Gustav Mahler's Ninth Symphony by the New York Philharmonic. Conductor Alan Gilbert stopped the orchestra until the phone was silenced. Betsy Vorce, speaking for Lincoln Center, says an announcement is usually made before every performance telling audience members to turn off their phones. If a device does go off, ushers discreetly ask the owner to turn it off. This time, when the iPhone went off, it was the conductor who turned his head to signal his displeasure. But the ringing from the first row persisted.
Gilbert asked that the offending noise be turned off and finally stopped the orchestra until it was.

Fortunately, this never happens in shul....:-)