This is useful but sometimes whats called 'Music Theory' is actually more like 'Music Notation' or 'Music Naming Conventions' and thats what most of this site is. IMHO for historical reasons the western naming conventions we've come up with for the 12 semitones (A, A#/B♭, B, C, C#/D♭, D, D#/E♭, E, F, F#/G♭, G, G#/A♭) actually obscure the underlying relationships between the notes rather then elucidating them. The same conventions get carried across to sheet music, where the overriding concern historically seemed to be saving ink rather than clarity.
The real 'theory' boils down to why the pattern of the major and minor scales is the pattern that it is (which is the same question as 'why are the black/white keys on the piano arranged that way?'). And the related question of why are there 12 of them in the octave.
And that underlying theory is much better explained in this page that was posted to HN some years ago:
'How Music Works'
https://www.lightnote.co/
Previous discussion: https://news.ycombinator.com/item?id=12792063 (2016)
Also see 'Music Theory for Nerds' https://news.ycombinator.com/item?id=12528144 (2016)
The real 'theory' boils down to why the pattern of the major and minor scales is the pattern that it is (which is the same question as 'why are the black/white keys on the piano arranged that way?'). And the related question of why are there 12 of them in the octave.
And that underlying theory is much better explained in this page that was posted to HN some years ago:
'How Music Works'
https://www.lightnote.co/
Previous discussion: https://news.ycombinator.com/item?id=12792063 (2016)
Also see 'Music Theory for Nerds' https://news.ycombinator.com/item?id=12528144 (2016)