Irish-born, Carroll has distinguished himself by taking an organic approach to film composing, using live instruments and employing discrete textured guitar. His credits include the thriller The Colony (Gold Medal winner at the 2008 Park City Film Music Festival); the dark comedy web series Hellholes; and the 2009 Sundance Film Festival critically acclaimed film The Horse Boy (co-composed with Lili Haydn). He is also a Sundance Composer fellow. As a guitarist, he can be heard on the soundtracks of Gone Baby Gone, The Chronicles of Narnia, Veronica Guerin and others..