What is this movie / animated art thing?

I'm trying to remember a movie (or actually it may have just been part of an animated series) it was similar to the sort of thing you might find randomly on like PBS. It had a lot of visual effects (I remember seeing it in HD when this was relatively new) and there was a protagonist who I believe was visiting hell, he never spoke (i think it was in first person) At some point I believe he meets the devil and also at some point he is in a place where various people are being tortured. One is under a sort of axe pendulum contraption. Another is being repeatedly put into a vat of acid, and another repeatedly being electrocuted. The last thing I remember is that the protagonist at some point begins to sing an opera (I believe Verdi's La Donne e Mobile) and yea.. can't really remember much it was a few years ago and I haven't been able to find what this was.