Isaac Fellman beat me to some, but not all of it:

“But what [Salieri’s] really doing, by railroading [Mozart] into a place of lonely illness, is forcing him to see only Salieri and recognize the million-watt intensity of his fandom. They haven’t invented the lamp yet that could be a good metaphor for Salieri’s fandom. He can only express it in candles, which must be frustrating.”

ANTONIO SALIERI, GROTESQUE WITH REMORSE, TRIUMPH, AND TIME: twas I who killed Amadeus Mozart, Padre, ‘twas I who brought down the curtain on the last and greatest concerto Europe ever hist – I killed him.

A SHIVERING PRIEST, TERRIFIED OF THE REAL: mein Gott…how did you do it

SALIERI: I befriended him

PRIEST: yes

SALIERI: I gave him a job when he needed money

PRIEST: I see, pray continue

SALIERI: One time I did not do him a favor even though I said I would do him a favor

PRIEST: yes, yes, go on

SALIERI: One time we stayed up all night and hummed together

and we talked about what happens after you die and I helped him with a project he was working on and we were perfectly in sync and we sang to each other for hours and appreciated one another perfectly and I told him to rest when he was pushing himself too hard and he told me I was his best friend and I watched him sleep

PRIEST: I see

SALIERI: My humming was sometimes quite full of resentment

fin