Freddie Highmore (August Rush), Keri Russell (Lyla Novacek), Jonathan Rhys Meyers (Louis Connelly), Terrence Howard (Richard Jeffries), Robin Williams (Maxwell Wizard Wallace), William Sadler (Thomas Novacek), Marian Seldes (Dekan) more..., Mykelti Williamson (Reverend James), Leon G. Thomas III (Arthur), Aaron Staton (Nick), Alex O'Loughlin (Marshall), Jamia Simone Nash (Hope), Becki Newton (Jennifer), Ronald Guttman (Professor), Bonnie McKee (Lizzy), Michael Drayer (Mannix), Megan Gallagher (Megan), Che Landon (Jane - Tutor), Jamie O'Keeffe (Steve), Tyler McGuckin (Peter), Anais Bonet (Backbeat), Bilal Bishop (Roller Bull), Michael R. Hammonds II (Feedback), Timmy Mitchum (Joey), Henry Caplan (Bill), John Knox (Club Manager), Amy V. Dewhurst (Receptionist), Victor Verhaeghe (Cop), Darrie Lawrence (Old Neighbor), Sean Haberle (Frank), Jamal Joseph (Driver), Robert Aberdeen (Record Executive), Georgia Creighton (Apartment Owner), Joshua Jaymz Doss (Orphanage Kid), Craig Johnson (Orphanage Boy), Dominic Colón (Policeman), Paula Rittie (Julia), Paul Thornton (Alcoholic), Jo Yang (Grande Dame), Logan Anderson (Philharmonic Patron) and others.

Richard Barton Lewis (Producer), Robert Greenhut (Executive Producer), Ralph Kamp (Executive Producer), Louise Goodsill (Executive Producer), Miky Lee (Executive Producer), Lionel Wigram (Executive Producer), William Steinkamp (Editor) more..., Michael Shaw (Production Design), Mark Mancina (Original Music Composer), Cathy Sandrich (Casting), John Mathieson (Director of Photography), Amanda Mackey (Casting), Nick Castle (Screenplay), James V. Hart (Screenplay), Paul Castro (Story), Nick Castle (Story), Carol Silverman (Set Decoration), Frank L. Fleming (Costume Design), Mario Ventenilla (Art Direction), Felice Diamond (Makeup Artist), Richard F. Esposito (Hairstylist), Gabrielle Jerou (Associate Producer), Robert Greenhut (Unit Production Manager), Bonnie Hlinomaz (Production Supervisor), Kate Bulpitt (Casting Associate), Farrah Fox-Collis (Casting Associate), Nicholas Bernstein (Location Manager), Cesar Quinones (Location Scout), Jessica Lichtner (Script Supervisor), Garson Yu (Title Designer),