AT THE START of A Late Quartet, Christopher Walken's character explains to a group of his cello students that Beethoven's late quartet, Opus 131, is not the standard four movements but instead has seven parts and that you have to play them straight through with no breaks, which causes your instruments to go all out of tune with one another. "It's a mess," he says.

It's also a metaphor about how basic entropy affects togetherness. The togetherness, say, of a musical group that's been playing together for 25 years when the oldest member finds he has Parkinson's and can't go on. Walken plays that character. Has he ever been the emotional center of a film before? It's magical. For much of A Late Quartet, the camera follows the storm of the other characters' drama—often, melodrama—until it finds a resting place once again on Walken's alien face, quietly registering the effects of old age, including the death of his wife.

If any pair of actors could mellow melodrama, it's Philip Seymour Hoffman and Catherine Keener. They play the second violin and the viola, respectively, of the Fugue String Quartet, of which Walken is cello. Mark Ivanir plays the driven, obsessive first violin; Imogen Poots is the just-post-teenaged daughter of Hoffman and Keener, a rageful, driven violinist herself.

The Parkinson's registers not only in the body of the cellist, but in the body of the quartet. Upon Walken's announcement, Hoffman decides it's time to announce his desire to share the lead, not just play second, as well as for more free-spirited readings of the music. Meeting resistance, he decides to fuck a hot dancer; not exactly a creative decision. Neither is the brief coupling of the two driven violinists of two different generations.

But the movie's central truth—messes get made, regardless of intentions—overshadows its tidy, clumsy Jenga of a drama because the performances are just that good. Walken is getting old. See him.