He was the music supervisor of films including The Last Emperor, Absolute Beginners, and Naked Lunch.
He was also a press agent for a number of major artists such as Sonny & Cher, Cream, Robert Stigwood, and for Brian Epstein's Saville Theatre.
He eventually moved up to head the A&R department for Liberty Records, where he signed upcoming artists who went on to achieve major successes with Jeff Lynne (Idle race and ELO), The Bonzo Dog Doo-Dah Band and Mike Batt, among others.
The Festival included performances by Paul Weller, Calvin Harris, Twisted Wheel and Raygun.
In 2019, Williams was portrayed by actor Charlie Rowe in the film Rocketman (which, he says, "mixed up all the stories" of what actually happened).