Dancing in a dream commonly reflects freedom of self-expression -- movement without self-consciousness, joy that doesn't need an audience's approval to feel real. Dancing with ease can point to a season where you feel genuinely yourself, while stiffness or embarrassment often names a self-expression you're still holding back.
The Moon hath a certain natural mutability, therefore she easily communicates to us the Influence of the other Stars. - William Lilly (1602.-1681.)