As I interpret it, a mask is what you wear on your face and a masque is a costume party or event at which people are in masks, for example Edgar Allan Poe’s story “The Masque of the Red Death.”

As far as I know they are synonyms. Either spelling is acceptable. I’ll be following to see what others say. Sending this to gailcalled.

@janbb I think you are describing a masquerade.

masque |mask| From my dictionary app.

noun

1: a form of amateur dramatic entertainment, popular among the nobility in 16th- and 17th-century England, which consisted of dancing and acting performed by masked players.

2: variant spelling of mask ( sense 1 of the noun).

I would not use them synonymously.

“I wore my mask while attending the masque.”: (masquerade or masked ball.

It seems to me that “mask” can be used metaphorically, while “masque” cannot:

__We all hide behind the mask of learning.__