Well, first we're dealing with variations on a specific tune. The reason I suspect that random variations might work well is that if the probability of a change is sufficiently low, it would have exactly the effect you suggest: mostly the original "Lullaby and Goodnight", but with occasional horrible. Of course, if I were actually a cruel genius, I could do better, but it would be foolish of me to admit to being one.
Another reason random changes might work well is that they are by definition unexpected. If I did something purposeful, it would have a pattern; the real Quirrell might break that pattern by observing his victim's reactions, but not having a pattern at all might also be an interesting thing to try.
My music theory is rusty and anyway underdeveloped. But I don't think individual notes can be disturbingly off key. It is the relationship between notes that takes them out of key. A single note of any frequency will produce harmonics with anything in the environment that is capable of responding, and thus create its own meager, on key accompaniment.
I think MIDI keeps you from even approaching the kind of terrible close but not quite right tones you want to reproduce.
The next discussion thread is here.
This is a new thread to discuss Eliezer Yudkowsky’s Harry Potter and the Methods of Rationality and anything related to it. This thread is intended for discussing chapter 84. The previous thread has passed 500 comments. Comment in the 14th thread until you read chapter 84.
There is now a site dedicated to the story at hpmor.com, which is now the place to go to find the authors notes and all sorts of other goodies. AdeleneDawner has kept an archive of Author’s Notes. (This goes up to the notes for chapter 76, and is now not updating. The authors notes from chapter 77 onwards are on hpmor.com.)
The first 5 discussion threads are on the main page under the harry_potter tag. Threads 6 and on (including this one) are in the discussion section using its separate tag system. Also: 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14.
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