Original first Printing , 17x22" concert poster for Crack Down, a benefit concert put on by Bill Graham at Madison Square Garden and the Felt Forum on 10/31/1986.  The concert featured Crosby Stills & Nash, The Allman Brothers, Run DMC, Santana, Babatunde Oltanje, and Ruben Blades.
 
Art by Keith Haring.   
The poster has some rippling and a water stain on one edge.  Otherwise very nice.