Beginning his musical career on lead guitar and accordion, he switched to bass in 1964, playing in numerous line-ups and backing chart artistes of the day such as Vince Taylor and Bert Weedon before joining soul band Lloyd Alexander Real Estate, which contained, or was associated with, the future members of Audience.

The band recorded four albums - the first for Polydor and the remainder for Charisma - scored a US Top 100 chart hit with "Indian Sumnmer" and performed over 400 shows over a period of three and a half years.

When Audience folded, Williams went on to play sessions for numerous artistes, also joining The Nashville Teens and Jonathan Kelly's Outside before retiring from the music business in 1975 to pursue interests in animal welfare, ultimately founding The Fox Project, a wildlife charity.

After a number of tours and individual gigs in the UK, Germany, Italy and Canada and recording live album, Audience finally folded in 2013 due to Gemmell's declining health and Williams' reluctance to continue with substitute musicians.

From 2009 until he retired from music in 2023, Williams played and sang lead for Blue Pulse, releasing, in May 2012, an album entitled Trams, largely featuring his own material.