We think of intervals between tones as being "the same" when there is a constant ratio between them. For instance, if two notes are an octave apart, the frequency of one is twice the other.
Thus, if we want to divide the octave into twelve semitones (which we do have twelve of: C, C#, D, D#, E, F, F#, G, G#, A, A#, B) and we want all of these twelve semitones to be the same intervals, then we want each interval to multiply the frequency by 2^(1/12).
Every part of that makes sense except for the lack of E# and B#, and why x2 is called an octave. Thanks for the info, and for reminding me why musical theory is one of three fields I have ever given up on learning.
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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