O’Callaghan previously had most of his work published by Discover, the British record label founded by John Askew. Recently, his work has been published by Armada Music and its subtags, especially Armind and Soundpiercing. The remix of his vocal trance production “Big Sky” by Agnelli & Nelson was voted “Tune of The Year” by listeners of Armin van Buuren A State of Trance radio show in 2007