After they left school they formed various bands, playing under names such as Stepping Stoned, Decade and Suburban Surfers (where they signed to manager Tom Watkins).
After nine months with Watkins, they left him and found a new manager in Tony Gordon, who had masterminded the careers of Culture Club and Curiosity Killed the Cat.
They eventually called themselves Ultra (named after the Depeche Mode album), and the following year Nick Keynes joined as bass player, after being introduced by mutual friend Neil Cowley.
O'Mahony, Harwood and Keynes set up a music production company, Goldust, writing and producing for other artists such as Bryan Adams, Kylie Minogue, Natasha Bedingfield, Gareth Gates, Sarah Whatmore, British Beef and Liberty X.
The Rebellion office is based in LA Sound Studios in West London, which is home to various other producer/writers including Steve Brown, Richard Spiller, Blue Flowers Music, Tom Garrad-Cole, Chris Hewitt and Martyn Corbet.