Remember mumblecore, the film movement that combined lots of earnest conversations, verité shooting style, indie rock and naturalistic performances? Launched the careers of Greta Gerwig and Mark Duplass? Andrea Dorfman was doing mumblecore back in the ’90s, before anyone thought to name it something dumb, with defiantly sincere films that culminated in her debut feature Parsley Days. Heartbeat is a similarly gentle, surprisingly funny, completely Haligonian drama about a lapsed artist (Tanya Davis) trying to find her voice again. She lives in her grandmother’s old house and goes to work in a bland office for a well-meaning but clueless boss (Jackie Torrens, reliably affable). She battles feeling for her ex (Stewart Legere) and falls for a drummer (Stephanie Clattenburg, of The Superfantastics), all the while fumbling back to her voice. Davis and Dorfman’s first collaboration, How To Be Alone, was a viral hit that spawned a book—their chemistry as artistic partners is palpable, and Dorfman has a great cinematographer in Stephanie Weber Biron, who’s shot most of Xavier Dolan’s films. The standout is Clattenburg, in her film debut, who turns in a sensitive, natural performance that keeps the movie firmly in our shabby houses, on our leaf-covered streets, wielding our instruments for all the world to see.