All of them got to kick back and enjoy the Jersey boys playing one of Jon's most memorable tunes, "Who Says You Can't Go Home."
Check out this video, obtained by TMZ ... Jon first introduced the person he called his "mentor" and "hero" before Bruce walked out on stage with an electric guitar. After Bruce hugged Jon, the rockers went straight into the song, dazzling the audience.
Other footage shows comedian Jim Gaffigan dressed as a 1980s version of Jon with a huge head of hair. Jim gave Jon a light-hearted roast, making everyone crack up.