Matthew Kelly began his musical career in the late 1960s, playing harmonica with some well-known blues artists, including Mel Brown, Champion Jack Dupree, Johnny Lee Hooker, and T-Bone Walker.

During this period, Kelly was also involved in the burgeoning rock music scene in the San Francisco Bay Area.

He played electric guitar and harmonica in several different psychedelic rock bands, along with fellow South Bay musicians Dave Torbert and Chris Herold.

In 1973, Torbert left the New Riders of the Purple Sage, and he and Kelly formed the band Kingfish, along with Chris Herold, Robbie Hoddinott, and Mick Ward.

From that time on, Kelly led a gradually evolving lineup of musicians, as Kingfish intermittently toured and released live albums.