MacLean's artwork captures the monikers of the performers: a modern-day Messenger streaks over the Grass Roots growing along the banks of a fast-flowing Mad River.
During the early days of the Fillmore, MacLean was the most "present" member of the staff. She collected tickets, passed out handbills, blew up balloons and counted money for Fillmore productions. Impressed with her lettering skill on the upcoming attractions chalkboards, Bill Graham surprised her with an easel and art supplies for Christmas, 1967, and MacLean's poster artist career was launched. Untrained in graphic arts, MacLean's early style evolved into ornate, Medieval-Gothic designs. Faces in her posters wore trance-like stares, steady and serene, and evoke the detached spirituality of the sixties.