Randy Bachman surprises David Letterman with a performance at Cleopatra’s Barge at Caesars Palace on September 6, 2018 in Las Vegas. (Photo by Denise Truscello/WireImage)

Randy Bachman surprises David Letterman with a performance at Cleopatra’s Barge at Caesars Palace on September 6, 2018 in Las Vegas. (Photo by Denise Truscello/WireImage)