 O'Doherty attended high school on Sydney's Northern Beaches, where he learnt classical guitar and later worked as a petrol station attendant.He appeared on stage with his brother's group in August 1977, initially filling in, and became a permanent member on bass guitar and vocals with Mombassa on lead guitar and vocals, Martin Plaza on vocals and guitar, Greedy Smith on vocals, keyboards and harmonica, and David Twohill on drums.Unlike other members of the group's classic line-up, he did not use any stage name for long