When I went to see the Furthur Festival in 2000, I didn't expect Hanson to come out and sit in for a few songs. I was also surprised that they were pretty good.
When I saw Springsteen in '99, I didn't expect Bonnie Raitt, Jackson Brown, Mary Chapin Carpenter and Bruce Hornsby to sit in for the encores.
When I saw REM in '99, I didn't expect to see Patti Smith come out and sing on "E-Bow the Letter".
When I saw REM this past October, I didn't expect Bill Berry to come onstage, sing backup on "Radio Free Europe" and play drums on "Permanent Vacation".