The film surrounds Evan, aka August Rush, an 11-year-old boy living in foster care, who wishes to find his parents again. He even claims that he can hear them through nature's music. Before he was born, his parents, a cellist named Lyla (Keri Russell) and an Irish guitarist named Louis (Jonathan Rhys-Meyers), met at a party, and after spending one night together, were forced to go their separate ways. They didn't know it then, but that one night would change their lives forever.
Soon after, Lyla learned she was pregnant, but after an accident, was told that she had lost the baby. Little did she know, the baby lived and would someday fight his way to find her again.