He regularly toured and recorded with Al Jarreau for over 3 decades and also was a musician on Michael Jackson's albums Off The Wall, Thriller, and Bad.

While at university, Williams began playing with visiting orchestras, including those of Glen Campbell, Henry Mancini, and Johnny Mathis.

[3] A notable part of the band's sound was the "Seawind Horns" (Williams with trumpeter Jerry Hey, and sax and flute player Kim Hutchcroft).

He encouraged the group to move to Los Angeles where they quickly established a regular gig at the club The Baked Potato.

[2] He has further recorded with Christopher Cross, David Crosby, Helen Reddy, Lee Ritenour, Lionel Richie, Mezzoforte, Michael Bolton, Michael Franks, Minnie Riperton, Natalie Cole, Olivia Newton-John, Pat Benatar, Patrice Rushen, Paul Young, Pink Floyd, Randy Crawford, Randy Newman, Ray Parker Jr., Richard Marx, Rick Astley, Roberta Flack, Sheena Easton, Simply Red and Stevie Nicks among others.