A clean first printing of BG-03, the poster known as BLUES ROCK BASH advertising an early 1966 concert by the Jefferson Airplane and Paul Butterfield Blues Band at the Fillmore Auditorium & UC Berkeley's Harmon Auditorium. This beautiful impression is in excellent condition; there are two small pinholes top center, a single one bottom center, a long flattened horizontal fold at the center, a crease at the bottom right corner, a few other small creases and some light handling–but as you can see from the photo, it looks overall very very nice. This poster comes the collection of the late Ralph J. Gleason (1917-1975;) one of the most influential jazz and pop music critics of all time. He was a central figure in the San Francisco rock scene, 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. This is a rare opportunity to obtain a poster from the personal collection of one of the key figures of the San Francisco Scene. On request, we will gladly provide a certificate of authenticity stating that this poster came from the Ralph J. Gleason Collection.