Original 1st printing 8&1/2 x 9" concert flyer for the Sparrow (proto-Steppenwolf) appearing at the Matrix in San Francisco, CA from 4/28-30/1967. 
 
 Artist unknown/not credited (looks like Leidenthal), thin flat pulpy stock flyer (PINK stock) is in very good to excellent (B/B+ to B+) condition; there are a few thin/soft edge bends scattered around the outer margin area, along with a tiny nip tear/pressure crease in the right center margin, a tiny soft bend in the bottom right corner tip and a loose soft handling ding or two lurking within the image area, otherwise fine.

 VERY nice-looking example of the PINK stock version of the always-popular "gooney bird" Matrix flyer.