Despite recovering from a series of serious medical issues which has seen him hospitalized several times in the past month, Michaels appeared on the show and performed the hit Poison ballad, "Every Rose Has Its Thorn," will Idol finalist Casey James.

"I needed to be here and do this," Michaels told the press backstage after his performance. "It's been two months since I played, a month and a half in the hospital, and it was such an amazing feeling to come out there tonight and jam with Casey."

"I needed this for my soul," he continued. "Honestly, this is a great experience."

He also addressed his health with reporters: "There's still obviously a lot of things and a lot of pain I'm still experiencing," he said. "But except for a little, as they say, hitch in the giddy up getting out there, my left side from the warning stroke, I feel amazing."

Michaels is planning to resume his solo tour this Friday in Biloxi, Miss.

As we hinted in yesterday's Day in Rock, Alice Cooper did in fact make a surprise appearance on the finale when he helped this season's finalists open the show with a rendition of his classic "School's Out".