Original 2nd printing (1st postcard printing ) 7 x 4&5/8 concert postcard forThe Jam, Mike Gravenaties, Mark Naftalin, The Byrds, and Pacific Gas & Electric at the Fillmore Auditorium in California on 2/6-9/1969.  The postcard has a "place stamp here" backing.
 
Art by Greg Irons, image is #159 in the Bill Graham/Fillmore series. 
 
Medium flat vellum stock postcard is in Near Mint/Mint (A-/A) ;  a fine-looking example of this early  postcard.