Whilst learning a trade as an audio engineer at DJM Studios in London at the age of 15, Guy also had a succession of his own bands and learned to play keyboards, guitars, and a variety of stringed instruments. He joined and toured with Steve Harley & Cockney Rebel in 1979 and in 1981, Roxy Music for their 'Avalon' world tour. In 1983, Guy was recruited by Dire Straits' lead guitarist Mark Knopfler to work on the music for the films Cal and 'Comfort and Joy. He joined Dire Straits in 1984, a year before their most successful album, Brothers in Arms, which put the band in a globally acclaimed spotlight.