I'm hoping they are planning for the Performance action menu to have its Dancer counterpart too... Don't know exactly how it can work, but I suppose something similar to the Bard.
Like a dance minigame interface, something like that Just Dance videogame, that let you combine a handful of different steps to create an actual dance.
Perhaps you could even have the option of summoning an NPC (like a Namazu playing an instrument), so you can have a track to dance upon.
I don't know, think of the possibilities of the second entertainer job!
PS: Please add an actual guitar to BRD too