For a brief period, McDonald and Melton performed together as a duo at college campuses in the Northwest on behalf of Students for a Democratic Society before returning as regulars at the Jabberwock cafe. The two were joined by local jug band musicians, including Melton's roommates, bass player Bruce Barthol and guitarist Paul Armstrong, and blues guitarist David Bennett Cohen, with whom Melton played in another jug band. The addition of drummer John Francis-Gunning rounded out the six-piece ensemble. It was during their residency at the Jabberwock that Country Joe and the Fish learned to play as a group and expand their repertoire. Within months, based on McDonald and Melton's interest in the live performances of the Paul Butterfield Blues Band, the recordings on Bob Dylan's album, "Highway 61 Revisited", and their use of the mind-altering drug LSD, the group began equipping themselves with electric instruments and delving more into psychedelia. As a result, Cohen was moved over to the organ. Cohen's experience with keyboards was limited to having played piano at a semiprofessional capacity at the Jabberwock, but, nonetheless, he quickly adapted to the qualities of the instrument. Melton describes the change of the group: "Once we hit into the electric medium and into the rock medium, we were pandering to the public taste. We became extraordinarily popular. The little folk club where we used to play once every two weeks, we played every single night for a month, or something like that, and filled it. And after a while we filled "two" shows every single night".