Safety first
How is he not listening to Duel of the Fates?
He's listening to a metal cover https://open.spotify.com/track/4UA3PrX0FPWmiBZfTxunz3?si=5DwOhjnySf2EqgPdO6uilw
I have always assumed that Darth Maul would be a classical opera fan. It my head maybe Wagner, but in the starwars world something similar from the creative faction of the nightsisters.
Then how about symphonic death metal? Examples include Septicflesh, Fleshgod Apocalypse, and Avatar of Hate
I am not familiar with any of those bands. I am very much looking forward to listening to them on your recommendation!