Mason's tenure with Traffic was disjointed. He co-founded the group, but left following the recording of their debut album, Mr. Fantasy (1967), only to rejoin halfway through the sessions for their next album, Traffic (1968), after which he left again. Last Exit (1969), a compilation of odds and ends, features little material by Mason apart from his song "Just for You". Traffic later re-formed without Mason, although he briefly began working with the band for a third time, touring with them in 1971 and playing on Welcome to the Canteen. In his brief spells with the group, Mason never quite fit in; Steve Winwood later recalled, "We all [Winwood, Jim Capaldi and Chris Wood] tended to write together, but Dave would come in with a complete song that he was going to sing and tell us all what he expected us to play. No discussion, like we were his backing group."
After Traffic, Mason pursued a moderately successful solo career. His first single was "Just for You"; on the B-side, "Little Woman", he was backed by the band Family, following his production of Family's first album, 1968's Music in a Doll's House (which included "Never Like This", an original Mason song). His songwriting and sound culminated on his 1970 album Alone Together featuring "Only You Know and I Know", which reached No. 42 on the Billboard chart, as well as the lesser hit "Look at You, Look at Me". In the early 1970s he enlisted his friend, singer-songwriter Ray Kennedy, to tour and write for his next album. In the mid- to late 1970s, he toured and recorded with guitarist Jim Krueger, keyboardist Mike Finnigan, bassist Gerald Johnson and drummer Rick Jaeger. In 1977, Mason had his biggest hit with "We Just Disagree", written by Krueger. Reaching No. 12 on the Billboard Hot 100, it was later successfully recorded by country singer Billy Dean. Mason played himself in the film Skatetown, U.S.A., performing two songs in a roller disco as well as writing and performing the film's theme song.
Mason in 2014
Mason's 1980 single, "Save Me", featured a duet with Michael Jackson. In 1988, a duet with Phoebe Snow, called "Dreams I Dream" reached #11 on the US adult contemporary charts.
Tenure in Fleetwood Mac
For a brief period in the 1990s, Mason joined Fleetwood Mac and released the album Time with them in 1995. In 1997 Mason was scheduled to be a member of Ringo Starr & His All-Starr Band, performing "Only You Know and I Know", "We Just Disagree" and "Feelin Alright", but he was dropped from rehearsals before the tour started.
As of 2005, Mason was performing about 100 shows a year with the Dave Mason Band across the U.S. and Canada. As of 2018, Mason was continuing to perform in the US.
Mason lived in the Ojai Valley in California for 16 years. As of September 2017 he had homes in Carson City, Nevada and Hawaii.
Mason is a proponent of music education for children. In 2005, he signed on as an official supporter of Little Kids Rock, a non-profit organisation that provides free musical instruments and lessons to children in American public schools. He sits on the organization's board of directors as an honorary member.
Mason also is a founding board member of Yoga Blue, a non-profit organisation devoted to teaching yoga and other holistic practices to those recovering from substance abuse and other self-destructive disorders.
Mason and his longtime friend Ted Knapp have founded Rock Our Vets, an all volunteer 501(c)3 charity supported by many other musical talents, helping veterans with whatever needs to be done, and the families of Law Enforcement and Firefighters who lost their lives in the line of duty. The charity has focused on providing food and clothing to homeless veterans, laptop computers for vets aspiring to continue their education, as well as suicide prevention.