4.25x7.25" postcard for Dec. 21-23, 1967 concert at Detroit, MI. Grande Ballroom featuring The Paul Butterfield Blues Band, Thyme, The Rationals, Cream, Billy C And The Sunshine, MC5, Soap and Trans Love. Two variants of this postcard were printed before the concert, these variants are a result of the "Split Fountain Technique" that was used. This is first printing, version B in lavendar on the left into orange on the right (variant A is orange on the left into lavendar on the right). Art by Gary Grimshaw features photo image of Ming the Mercilous from Flash Gordon serials of the 1940s. Original owner, an acquaintance of the artist, had them personally sign this in black ink along bottom margin. Lt. handling wear. Exc. Scarce.