Karaoke is, or has been each time I have cruised Princess, done each night for five nights. The winners usually perform the last night of the cruise for the final winner.
They have had it on every cruise I have been on including one that I took on the Crown. It was called "Princess Pop Star". As earlier poster said - some are good - some are not so good - but EVERYONE- has fun. It was held every night at 11:00 at Club Fusion. Enjoy!