Middleton began guitar in high school, influenced by Twisted Sister and AC/DC, and began playing in clubs around his hometown of Brisbane as part of his first band, Sonic Tapestry. He went on to form another band, Pirate, with high school friends, and met Powderfinger at a Pirate show. He was invited to join the band, and did so. Middleton took part in all of Powderfinger's recordings, at the same time writing and releasing an EP and studio album with Drag.