Here's my "programmer's version" of music theory: * We've evolved to hear a wide range of frequencies from elephants stampeding (~60Hz) to flies buzzing (~200H

Here's my "programmer's version" of music theory: * We've evolved to hear a wide range of frequencies from elephants stampeding (~60Hz) to flies buzzing (~200Hz) to birds singing (~KHz). To accommodate this, our ears work logarithmically so an exponential increase in frequency is "perceived" as linear progression. * Melody, tempo and cadence of a tune are linked to how we speak, with the melody following the syllable pattern and tempo of our human language speech [1]. This is also potentially why you get 1/f frequencies when analyzing music, because human language, speech and word frequencies follow power laws themselves [2]. * Discretizing steps between the frequency doubling helps express and communicate music. * For whatever reason, when combining frequencies we tend to "like" simple ratios of one frequency to another, preferring a small a integer numerator and denominator (maybe this is a consequence of the logarithmic pitch detection?). Discretizing a frequency doubling into 12 steps offers a happy compromise of having many combinations of frequencies that have a small reduced fraction approximations [3]. * From the simple reduced fraction idea you can "derive" why notes close together sound 'dissonant' (large numerator and/or denominator in approximated fraction) and how to construct musical chords as they're 2-3 frequency combinations that have a good pairwise small reduced fraction approximation. * Musical scales or modes are the result of further restricting the 12 step octave to a reduced set that have nice pairwise reduced fraction approximation (e.g. "sound nice"). The modes ionian, dorian, phrygian, lydian, mixolydian aeolian and locrian are the 'step sequence' of [1,2,2,1,2,2,2] (take 'c' as root, then move one over, then 2, etc.) rotationally permuted (8 steps, 8 modes). For example, ionian has step sequence [2,2,1,2,2,2,1] (e.g. [c,d,e,f,g,a,b]) whereas dorian has step sequence [2,1,2,2,2,1,2] (e.g. c,d,d#,f,g,a,a#]). This is my understanding so far. I haven't made any music that I would remotely call "good" so all this should be taken with skepticism. This is also heavily biased towards western music and I think there are many exceptions from around the world of different cultures producing different music that might not be classified from the above. [1] "An empirical comparison of rhythm in language and music" by Aniruddh D. Pate, Joseph R. Daniele (https://www.researchgate.net/publication/10976378_An_empirical_comparison_of_rhythm_in_language_and_music https://www.researchgate.net/publication/10976378_An_empiric...) [2] "Musical rhythm spectra from Bach to Joplin obey a 1/f power law" by Daniel J. Levitin, Parag Chordia, and Vinod Menon (https://www.pnas.org/content/109/10/3716 https://www.pnas.org/content/109/10/3716) [3] "Measures of Consonances in a Goodness-of-fit Model for Equal-tempered Scales" by Aline Honingh (https://www.researchgate.net/publication/267806865_Measures_of_Consonances_in_a_Goodness-of-fit_Model_for_Equal-tempered_Scales https://www.researchgate.net/publication/267806865_Measures_...)