Oh, how could I have forgotten Wandering Minstrel?
And here I was expecting Sir Robin's minstrels from Monty Python and the Holy Grail [1].
So often the optimal number of Heroes you want to get is 1 which you exchange into a Champion and you want to keep the Warriors for the draw. This means the right thing to sing when MFs Exchange Screen pops up is: "We don't need another Hero."
... and for those exceptional times: Bonnie Tyler I need a Hero [2].
In games with lots of Gold-gaining, my friend and I often sing Gold by Imagine Dragons.
When I was 80% of the way through that sentence, I expected it to end with "by Spandau Ballet" [3].
Some of my favorites are:
Masquerade: Rainbow Black Masquerade [4]
Throne Room: John Williams Throne Room [5]
[1]
[2]
[3]
[4]
[5]