He is best known for his bass work with the punk rock bands Operation Ivy, Rancid and as the frontman of Devil's Brigade.

Although Armstrong and Frederiksen are the principal singers in Rancid, Freeman has taken the lead vocal duties in a number of gritty sounding songs through the years, including the songs "Black and Blue", "Rigged on a Fix", "Black Derby Jacket", "Tenderloin" and, "L.A. River".

Freeman was also the primary co-lead vocal for the first Rancid album, before Frederiksen joined the band, with his role subsequently being reduced by choice.

Their partnership has continued with Freeman contributing basslines to selected tracks by the Transplants, one of Armstrong's side projects.

During Rancid's 2004 hiatus, Freeman replaced bassist John Maurer in Social Distortion shortly before the release of their then-new album Sex, Love and Rock 'n' Roll.

Freeman did not intend to stay in the band permanently and he was replaced by current bassist Brent Harding in late 2004.

[2] Following his departure from Social Distortion, Freeman was diagnosed with lung cancer in May 2005, but was dismissed as abnormal tissue growth and not terminal to his health in June 2005.