Writer/director John Carney, the filmmaker behind the charmer Once, his previous movie in which he used music to tell a tale that was authentic yet familiar, unique yet universal, makes a second attempt at using the world of musicians to touch upon souls at crisis. Unfortunately Begin Again falls short on all accounts. It is corny, predictable, and cutesy. It is also misguidedly casted, at least as far as the leading roles are concerned. Though Keira Knightley tries her best, she is just not a great fit for the part, nor is Mark Ruffalo who overplays his character. 
Begin Again does enjoy several sincere moments, a few decent pieces of music, and an occasional laugh, but all in all, it is a disappointment. It tries too hard where flow is needed, it is overdramatic where a lighter touch is called for, and it lingers on and on where better pacing could have saved the day. Once it is not; begin again, it should.