Neil Young, right, and Crazy Horse with guest Willie Nelson.
Dave Matthews at the press conference.
Willie Nelson laughs before sharing the stage with Neil Young.
John Mellencamp at the press conference.
Willie Nelson earlier in the day.
Dave Matthews speaks at the press conference.
Jamie Johnson performs.
Willie Nelson introduces Jack Johnson onto the stage.
Andy York, left, John Mellencamp, and Mike Wanchic perform.
Grace Potter rocks in out on stage.
Willie Nelson welcomes the crowd to Farm Aid.
The guitar of Jamie Johnson.
Willie Nelson performs near the end of the show.
Jack Johnson entertains the crowd.
Dave Matthews performs "Funny the Way It Is."
Tim Reynolds, left, and Dave Matthews perform.