Paul Simon, who officially retired from touring last year, has made it known that he hasn’t retired from performing, especially for causes he believes in. Paul appeared at Outside Lands Festival this past weekend and chose the San Francisco Parks Alliance and Friends of the Urban Forest to benefit from his appearance.

For the encore, Simon welcomed an old friend to the stage—Bob Weir. Here is what Paul said as he welcomed Weir to the stage:

“Well I have an old friend who is coming out to join me tonight… I met him in 1967… I was coming up to the Haight-Ashbury to invite The Grateful Dead to join the Monterey Pop Festival. I knocked on the door of their house, and Bob Weir opened the door… and we’ve been friends ever since! But actually, this is our first duet! “

Bob joined Paul for Simon’s “The Boxer.”

Thanks to AdmiralNeeda for the great front row footage!