The Virginia senator, 58, played the harmonica while Bon Jovi belted out his 1986 track, "You Give Love a Bad Name," at a Get Out The Vote rally at The State Theater in St. Petersburg, Florida.
Bon Jovi -- who played a few other songs, including "Living on a Prayer -- joked that he would start a band called "TK and the Faithful."
"You guys should know that every single one of you your vote really matters," the New Jersey native said. "It's very important that you know that. In fact, there are fewer people here in this room that decided the election of 2000, and we all [know] the impact that that had ... So do what you can to make sure your voice is heard, that your friends and your families all get out and vote on Tuesday."
ABC News' Jessica Hopper contributed to this report.