John Mayall, Bo Diddley, Muddy Waters, Otis Spann, and Magic Sam, Original Vintage Concert Poster. A veritable masterpiece by the late, great Greg Irons. The poster is for a Blues extravaganza featuring John Mayall, Bo Diddley, Muddy Waters and more. A real pantheon. The shows took place at Winterland Ballroom in San Francisco, California, March 27-29, 1969 The artwork is sublime. Greg Irons has brought his talent to the fore with this piece. The lettering, color choices, and composition all add up to nothing less than a graphic design tour de force. Just an absolutely beautiful piece. But there’s more. Elegantly elongated, the poster measures 13 5/8” X 28 5/8”. The piece is in very good condition, two very small tape pulls at the top, pinholes on corners. Colors remain bright and strong. Astonishingly vivid. The poster does not have ticket outlet information at the bottom.