Dean began composing in 1988 initially focusing on experimental film and radio projects as well as improvisational performance. Since then, he has created numerous compositions, mainly orchestral or chamber music as well as concertos for several solo instruments. His most successful work is "Carlo" for strings, sample and tape, inspired by the music of Carlo Gesualdo. On 7 September 2008 his work "Polysomnography" for wind quintet and piano received its world premiere at the Lucerne Festival; on 2 October 2008 Simon Rattle conducted the first performance of the orchestral song cycle "Songs of Joy" in Philadelphia. His first opera, "Bliss", based on the novel by Peter Carey, premiered at Opera Australia in 2010.