An incredibly rare 7" EP produced in 1966 by Sound City Productions to promote the highly collectible "Acid Test" album. This features excerpts from the album, with the Grateful Dead improvising while Merry Prankster head Ken Kesey and Prankster Ken Babbs speak–all while under the influence of LSD. Only a few copies of this very rare EP have ever surfaced, and this one is in exceptional NM- condition, having been played once or twice at most. This record was originally owned by Ralph J. Gleason (1917-1975;) one of the most influential music critics of all time. A central figure in the San Francisco rock scene, he wrote at length of Kesey, the Dead and the Acid Tests in his book "The Jefferson Airplane and the San Francisco Scene"–the first book on the subject. Gleason helped organize the Monterey Pop Festival and co-founded Rolling Stone magazine. Bill Graham himself credited Gleason with suggesting the Fillmore Auditorium to him as a site for concerts, while the Family Dog met with Gleason at his home to discuss their idea to stage dance concerts, prior to their first show at the Longshoreman's Hall. When the organizers of the Monterey Pop Festival had trouble recruiting the San Francisco bands, they turned to Gleason and Bill Graham, who were able to convince the major acts to come on board. We purchased this and much of Gleason's record collection directly from his family. An exceptionally rare Acid Test/Grateful Dead artifact with superb provenance.