The ABB and Cowboy played at the Schaefer Music Festival in Central Park, NY on July 21, 1971 and NOT on July 21, 1970.
More info on: http://www.fillmore-east.com/schaefer.htm
The 1970 program is on: http://www.fillmore-east.com/schaefeprogram70_10.htm and: http://www.fillmore-east.com/schaefeprogram70_11.htm
Duane Allman played on August 5, 1970 at the Schaefer Music Festival with Delaney & Bonnie & Friends