The spring of 1967 was the heyday of the Avalon Ballroom and dances like these. Janis Joplin was beginning to stand out as represented in this poster by Rick Griffin which has a little bit of an old western dance-hall feel to it. Others have pointed out the subtle sexual overtones with the penis-shaped photograph, Janis Joplin occupying the "head" from her breasts up, all the other members pictured close to her waist, and "Down on Me" being the band's current single. Considering that Griffin spelled the poster MotherLoad instead of Lode, they may be right…
"Combination Of The Two," the opening song of Cheap Thrills, the second album by the Big Brother and The Holding Company, was a homage to the rock ballrooms of San Francisco, and there is a direct reference to the Avalon in the lyrics: "Everybody over at the Avalon Ballroom in the San Francisco Bay". According to Sam Andrew in the documentary Nine Hundred Nights, he wrote “Combination of The Two” for the San Francisco late 60s scene, and "The Two" were The Fillmore and The Avalon.