I could use a hint as well.
Observations so far:
Click here to view the secret text
×* Beethro's dialogue on entering the room suggests replacing A with O.
* Given the choir theme, and "Three eighths" on the scroll next to the slot machine puzzle, I am assuming the last word is NOTE.
This leaves me with O?? ?????? ON ?????-NOTE but there are so many one-use letters, I'm not sure how to go about solving the rest of the cryptogram.
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136th Skywatcher
surrealcanine plays All the DRODs