How often does the entertainment schedule change on Explorer of the Seas (Alaska)?

I was comparing the compass from the Seattle/Alaska sailing at the end of May to the one that is currently being posted for this week. I noticed that some of the entertainment has changed between the 2 sailings. Does anyone know of how often they change performers/shows? Not a big deal, I just thought there would be more consistency between sailings, especially two so close together.

Thanks!

Regular Royal Main stage performers(singers/dancers) stay on, then some entertainers will be on 1-2 sailings then more on to other ships or cruise lines..

The production shows stay the same forever...there are guest performers that switch out every couple of days.