Original  4 & 1/2 x 7" concert postcard for Hello People, Iron Butterfly, Canned Heat and Initial Shock . at the Fillmore Auditorium in San Francisco, CA on 7/30-8/41968. 
 
Art by Lee Conklin, image is # 131 in the Bill Graham/Fillmore series. 
 
Postcard is in Near Mint/Mint (A-/A) ;  otherwise a fine-looking example of this early Fillmore postcard.