Tom Selznick (Elijah Wood) is a famous concert pianist under a lot of pressure. He's performing after five years of retirement on a Grand Piano that belonged to his dead mentor. As if that wasn't enough, his wife Emma is a top Hollywood actress, so there's a full house. At the beginning of the show he notices a note written on the music sheets which says that he'll die if he performs one wrong note. There's a guy (John Cusack) with a rifle up in the rafters and he threatens to kill Tom's wife he he screws up.
Tom tries texting for help from his cell phone but ends up getting two friends killed by the guy's henchman. In the end, things escalate from this psychological attack on him and his performance to a very physical one high up in the theater.
It's interesting that half the movie happens in real time, sort of like Hitchcock's ROPE, which I'm sure was an inspiration for this movie. Also, the film's best actor is not Wood or Cusack but Alex Winter (LOST BOYS, BILL & TED) as the sniper's murderous henchman. Unfortunately the movie is flat and so surreal that I expected it to be revealed that "it was all a dream", an ending I always despise. But when that didn't happen I was actually disappointed.