Bar bands usually have certain ‘fall back’ covers to lean on when the gig outlasts their material (or attention span). When in doubt, go to Chuck Berry, Elvis, Buddy Holly…. or this classic from Billy Halley And The Comets.[audio:http://home.comcast.net/~wolfdog98/cover04.mp3]
Don’t need to remember the words, just get the key phrases out there.
And let Bob rip.