"Showdown" is a name given to the real-time multiplayer part of the game.
The showdowns are different "rooms" where is hosted a playing platform for multiplaying a chosen song.
This feature also provides a chat room where players can chat before and after each song played.
The Showdowns can either be public or private (a password is required to enter it).
Duels vs. Showdowns : Duels are one-on-one challenges, where both players can play whenever they have time. Showdowns let many people play the same song at the same time and compete in real-time. Furthermore, in Showdowns players only play GuitarJam, whereas Duels can be with both BeatJam and GuitarJam.