John O’Callaghan is an Irish musician and DJ, mainly producing trance music. He also produces music under the alias of Joint Operations Centre, Mannix, Henrik Zuberstein and Stenna. He has also collaborated with fellow Discover artists such as Bryan Kearney, Neal Scarborough (as Inertia), Thomas Bronzwaer (as Lost World) and Greg Downey as well as more recently, trance hero Leon Bolier. His best known track is “Big Sky”, done with vocalist Audrey Gallagher. Callaghan has received remixes by trance artists such as The Thrillseekers, Sean Tyas, Gareth Emery, Cosmic Gate, Markus Schulz and Indecent Noise. He has also worked with Heatbeat and Aly & Fila.
The remix of his vocal trance production “Big Sky” by Agnelli & Nelson was voted “Tune of The Year” by listeners of Armin van Buuren’s A State of Trance radio show in 2007.
In 2008, not only did John enter the DJ Mag 100 at number 60 but he also picked up two awards at the Irish Dance Music Awards, winning Best Producer and Best DJ. With the success of 2008 flowing, John also became the first Irishman to play Trance Energy. In 2009, he rose 36 places to 24th in the DJ Mag 100.