Interesting enough to note, there have also been a few songs that seem specifically oriented to the Man in the Iron Mask.

Black Sabbath-Iron Man
with lyrics like:
Nobody wants him
He just stares at the world
Planning his vengeance
That he will soon unfurl

And

Styx-Mr. Roboto (not all of it naturally)
But the lyrics hint at knowledge about the Iron Mask.

As I was reading the posts, these two songs popped in my head immediately as stand outs about individuals wearing masks and what may really be going through their minds.
T