Label founded in 1964 by Bob Shad, who also ran the Sittin' In With, Jax, Jade, Shad and Time Records (3) labels. Mainstream issued many new recordings such as the first records by Janis Joplin and Ted Nugent, though also reissued many of the titles from the Shad and Time Records catalogs.
Among the titles reissued were the 10 titles in Earle Brown's Contemporary Sound Series, to which they added 8 more titles.
In the early 1990s, Bob Shad's daughter Tamara Shad revived the Mainstream label to reissue a number of the jazz and blues recordings from the label on CD. In 1993, Sony acquired a large portion of Mainstream's catalog for reissue.