Ask HN: How Can I Learn Music Theory?

Realizing that every note was basically the same and all semitone intervals are the same, I asked myself the "innocent" question, then why are they labeled black and white on a piano keyboard?

Trying to answer this question to my (full) satisfaction took me on a very deep google dive, several over a couple of years in fact. But it roughly led me through most areas of music theory. I'm still not entirely satisfied with the explanations I found, but some of the remaining questions are also kind of open in music theory.

It comes down to the question of what's so special about the major scale? And the answer is kind of in the circle of fifths and combinatorial music theory. If you have a modulo 12 system (because octave equivalence, which seems to be a physiological property of human hearing), there are two generating primes, 5 and 7. These correspond to a fifth down or up. Generating prime means that it generates all the 12 notes if you follow it modulo 12. Also it turns out that the complementary scales of the major (7) and the pentatonic (5) are "maximally even" (IIRC), .. and now I forgot why that was important. It's complex stuff.

There's also reasons why we got 12 notes instead of 10 or 16. Mainly to do with how close you can get to simple fractions of frequency ratios. You also have 19-TET, which has more notes and gets pretty close, but 12 is still superior in some ways afaik. This is the part that I found really interesting, but over time it's been nagging at me: Simple frequency ratios are special because their waves and harmonics coincide in periodic fashion. But if it's good enough to just be "close enough" to some ratio, that is actually equivalent to exactly hitting a much more complex fractional ratio. The accepted reasoning is, I guess, that human hearing is kind of fuzzy and not too fussy about these things. But that feels a little bit too hand-wavy to me. Especially cause the fuzzy can be trained, and most of us expect to hear the particular 12-TET tuning, and when they hear the exact ratios, they sound kind of "off". So I feel there's still some understanding missing from this theory, or at least more I'd like to learn (somewhere between physiological human hearing and cultural music theory of scales from all over the world and history).

I kind of feel like I learned about music "in reverse" this way, and I'm not sure I'd recommend it as the way to study music theory, but it sure as hell has been interesting.

This is so true. I've been wanting to learn about rhythmic theory for about as long as I've been studying music theory (harmony). But while you can find youtube videos and webpages full of explaining musical harmony all over the place, information about rhythmic theory is far and few between.

Most I've been able to find is either very abstract, like Euclidean Rhythms, which are interesting and weird but only explore equidistant grids (no swing). The other information is usually about really specific cultural rhythms. Both are good and useful, but I feel like they combine into less than 20% of the total theory about rhythm that I believe should be there. There's really a lot to it and I'm still looking for some fundamental theories about repetition and expectation and tension/release. The latter is very important in rhythm, but as far as I'm aware, the music theory about harmonic tension and release (chord progressions etc) seems so much more complete than what I've been able to find about rhythm.

If you got any good pointers, I'm all ears :)

And apparently the human ear can be train to ignore this slight difference (which everybody does because we are used to 12-TET). And this, for me, kind of throws the whole "simple integer fraction ratio == pleasing harmony" a bit into question. It's probably not wrong, but there's definitely more to it. But it's hard to explore, because you need the exposure to get used to the new microtonals if you want to experiment with it. Definitely very hard to test scientifically because it depends so much on a particular person's musical background and education.

The system is most useful for describing / exploring certain types of atonal music. I’m going to make an unfair generalization—most people are interested in tonal music. You can see that the references here are to Forte’s The Structure of Atonal Music and Rahn’s Basic Atonal Theory. So if that’s your jam, by all means, go and make atonal music. But I’m a fan of using modes of common scales, so I like having concise names like phrygian, mixolydian, and dorian.

There are specific resources given for beginners.

Personally I went with the large The Complete Musician by Laitz as most recommended it, and I’m quite happy with my choice.

It goes very deeply into all aspects of playing and composing music as well as understanding it.

The style Is a bit academic but the overall level is quite accessible and very clear.