Even though Club Penguin’s 2014 Music Jam is still over, it is still possible to access the party’s rooms. If you liked the party enough that you wanted to revisit it, then login to Club Penguin with this URL and you still start off in the cruise ship’s lobby.
You cannot get any items and there are no performances, however you can still waddle around all the rooms. There is no risk of a ban however do this at your own risk!
Instead of the Music Jam music you will hear Operation Blackout music. This is normal when you access a party after it’s over. It’s just the way things are.
Enjoy it while it lasts, as usually Club Penguin fixes this pretty quickly!