Rascal Flatts sang "I Won't Let Go' on the finale of the Oprah Show that was taped on May 17th...Watch it here.

Zach Henderson

Rascal Flatts were chosen to make a unannounced appearance at the Oprah Winfrey Show's finale. 'Surprise Oprah! A Farewell Spectacular, Part 1' was taped Tuesday May 17 before an estimated 13,000 fans at Chicago's United Center.