So I don’t know a ton about music theory, but I’m curious about how this works. Why do our brains like to hear chords that are in tune? And how do we explain why something is tuned properly?
In: 32
Definitely not ELI5, but this article is one of the best I have read which tries to explain “why” music works. I’ll try to summarize the very basics of it:
To survive, we need to be able to distinguish between different sounds. There is a part of your brain that compares sound frequencies and decides if they are the same or not, and how far apart they are if they are not the same.
Audible frequencies cover a HUGE range. It would be inefficient to have “hardware” in your brain that can work over that entire range. So, your brain only does the comparisons over a limited range of the audible frequencies. But, it divides or multiplies by 2 the frequency of any sound that falls outside that range, until the new frequency IS inside the range.
This means that sounds whose frequency are related by a factor of 2 get flagged as being “the same”. These are octaves. We interpret these as sounding “good” together.
From there, the article shows that the simpler the ratio between the frequencies of two sounds, the “better” it sounds. So a ratio of 2 (the octaves) sounds great, 3/2 is pretty good, 5/4 is not bad, and it gets “worse” from there.
I cannot keep the rest of it simple, but for a variety of reasons, we don’t build instruments that perfectly match these ratios, and things get complicated the more notes you play, and your brain can play tricks to “fill in” missing frequencies in a sequence. Highly recommend studying the article if you find this interesting. It really helped me make sense of apparently arbitrary music notation and theory.
[Harmony Explained: A Progress Towards A Scientific Theory of Music](http://chrome-distiller://2dc3a6c0-91fd-4cc8-8090-5aa6f47e82c2_b1fabce9e4e980408c2d35279c81722a34e89d7f1e2aa1d3f5ad4fdf6e062b0b/?title=Harmony+Explained%3A+Progress+Towards+A+Scientific+Theory+of+Music&url=https%3A%2F%2Farxiv.org%2Fhtml%2F1202.4212v1)
Frequency interpretation.
A single note that resonates is easily understood and interpreted.
Notes beside each other cause an interference banding of harmonics. They are dissonant and easy to dislike because they are difficult to interpret or recognize.
There are certain intervals that are basically mappable by how universally pleasing they sound (it’s got to do with relative frequencies, I know it starts with octave, then 5th, and after that I get less sure), but the same can’t really be said for chords. Chords are all about context, [Adam Neely](https://youtu.be/lz3WR-F_pnM) and [Jacob Collier](https://youtu.be/EWHpdmDHrn8) have great videos that come at it from different directions.
It is mostly context that makes chords sound “better” or “worse”. There is still no right or wrong chord, and better or worse is up to you as a listener.
Harmony, or how notes sound together, basically falls into two kinds, consonant and dissonant. Consonant is very nice sounding, while dissonant is a bit tense.
You might think that a tense sounding chord is a bad sounding chord all the time, but it isn’t. These chords are made to sound good by giving it context.
Maybe in one case, it is used so that a consonant sounding chord played after it will sound even more satisfying. A dissonant chord may also come after a consonant sounding chord to make the listener feel more emotional than another consonant chord would make them. So while a dissonant cord sounds “bad” on its own, it becomes good when it is in the right place.
The same goes with harmony and melody. The melody can be the same, but the chord. Being played with it can produce the same satisfaction or tension depending on how the melody changes the chord.
As to why something is tuned properly depends on what the standard is. There are many different types of scales and instrument tunings. All one has to do is follow these tunings. If your individual notes do not stick to the tunings or scales, then it is almost sure that you’re out of tune.
Keep in mind that being in tune one way doesn’t mean you’ll be in tune another way. For example, Indian music will sound out of tune when compared to western pop music because Indian music can use notes that aren’t even present on the keys of the piano.
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