Meet Dan (
Mark Ruffalo). Dan's life is not going well at the moment - his marriage collapsed, he can't connect with his teenage daughter, he drinks way too much and he hadn't had a professional success - in his job as a music producer - in 5 years. One evening, after a particularly shitty day, Dan goes to a bar to get drunk. As he is drinking he hears a song. A song sang by a girl named Gretta (
Keira Knightley) on the stage. Immediately Dan wants to sing Gretta up. But as things don't go as they planned, the two decide to record a live album in different locations in NYC. As they do that, they start getting closer to each other and finding something that they didn't have in their lives in a long time - joy.