By the mid-'60s WBRU was considered an alternative station in that much of the music was folk and rock. Joni Mitchell, Richie Havens, Joan Baez had a home on this station and were not yet on mainstream radio. After 1966 much of the music format was not mainstream. The station was considered an "Underground Rock Music Station" similar to Boston's WBCN. The station's playlist featured artists such as Frank Zappa and The Mothers of Invention, The Fugs, Pearls Before Swine, Phil Ochs, Country Joe & The Fish and other left-leaning rock acts that were not typically played on mainstream radio.