He was one of England's most utilized session bassists during the 1970s and 1980s, including for Jeff Beck as well as for the Rod Stewart band from 1977 to 1980, but is probably best known for his later work with Ray Manzarek and Robby Krieger of the Doors.

He first joined Jimmy James and the Vagabonds in 1965,[5] before realizing that he could make much more money as a session musician.

Chen also joined the Butts Band, led by Doors guitarist Robby Krieger and drummer John Densmore, and recorded their 1974 self-titled debut with them.

Chen joined Rod Stewart's band performing on three of his albums, Foot Loose & Fancy Free (1977), Blondes Have More Fun (1978), and Foolish Behaviour (1980) and performed on some of his biggest hits: "Da Ya Think I'm Sexy?

[5] Other musicians with whom Chen performed and recorded include Pete Townshend, Eric Clapton, Ray Charles, Desmond Dekker, Jerry Lee Lewis, Bob Marley, Jimmy Cliff, Jackson Browne, Dave Edmunds, and Linda Lewis, among others.