It wasn't at Disney, but at IOA. Earlier in the year, my friends and I saw Chris Daughtry and his band there. We were there for the Mardi Gras concert series and he was performing that night. Anyway, my friends decide to ride Dr. Doom, which is one ride I refuse to do. They get off, and my friend says "Call me crazy, but I think Chris Daughtry from American Idol was right behind me in line!" Sure enough, a moment later, he and his entire band walk out of the exit, escorted by an employee. It was pretty cool! I'm really surprised they didn't offer him front of the line access, or maybe they did, and he refused it.
We never saw his concert either -crowds starting lining up for it over 2 hours ahead of time, and my friend's gf was tired and didn't want to hang around.