From Jesse McCartney to Demi Lovato, here's who the Jonas Brothers have surprised fans with on their Jonas20 Tour, so far.

The Jonas Brothers have been through their share of ebbs and flows, but as they celebrate their 20th year with a new tour, they've mastered the magic that keeps fans coming back.

The "Greetings From Your Hometown" tour faced thunderstorms and rain, but delivered fan favorites, special guests, and even a ...