Once director John Carney delivers his signature charm to this breezy, fun romantic musical. Mark Ruffalo as a disgruntled, burnt out music producer and Keira Knightley as a heartbroken indie artist works in a weird way. What can we say? The chemistry between the two leads is solid, and the bops are catchy. We're also a little obsessed with the star-studded cast, which includes Catherine Keener, Hailee Steinfeld, and even Adam Levine himself.