I think you will really enjoy your cruise. The "Class System" is not as distinct as you might think. While Suites and Aqua do have separate dining rooms most guests still socialize in the same public spaces.
They do have a Theater for evening Shows and Lectures there is also a Movie Theater that is also used for late night comedy and other things.
Music done throughout the ship with most sets lasting 50 minutes. They will perform in different Bars, Main Foyer, al Bacio, Sky Lounge, Pool Stage, Ocean View outside area.
You may wish to download the Celebrity App - You can choose an existing sailing and go to cruise planner (un-filter from recommended to all) and you can view a representative listing hourly