Western music consists of twelve notes grouped into seven white and five black notes according to the piano keyboard. Come on, seven natural notes and five accidentals. Why this such a random arrangement? Mathematics is the protagonist of a story of passion and debauchery between quotient sets and frequencies that please the ear. * * * Additional information and bibliography: https://lemnismath.org/2018/09/por-qu... Instagram: / lemnismath Twitter: / lemnismath * * * Since you have continued reading up to here, one more thing. Note that the equal temperament arrangement is a kidney stone of sound theory. At first we were looking for sounds that fit together because they followed simple relationships (1/2 or 2/3). If now the relationships depend on the twelfth root of two (an openly irrational number) we will never be able to express them as a fraction. That is to say, ALL the sounds of the chromatic scale are dissonant with each other. Let's take a breath of fresh air with the theory. Luckily, the human ear is not so picky and has a hard time distinguishing these small differences in the frequency of sounds. That's why the scale still sounds in tune to us, even though mathematically it is not. ---------------------------------------------------------------------- Things I've used: Whoosh sound: https://freesound.org/people/ztrees1/... Bamboo sound: https://freesound.org/people/Inspecto... Photo of the chinacos playing: https://commons.wikimedia.org/wiki/Fi... And the ear hair: https://www.flickr.com/photos/richard... The guitar: https://commons.wikimedia.org/wiki/Fi... And the music: Dances and Dames by Kevin MacLeod is subject to a Creative Commons Attribution license (https://creativecommons.org/licenses/...) Source: http://incompetech.com/music/royalty-... Artist: http://incompetech.com/ Some of the others, with the help of Perancha. ----------------------------------------------------------------- Following the line of: Carey, Norman & Clampitt, David. (1989). Aspects of Well-Formed Scales. Music Theory Spectrum. 11. 187-206. 10.1525/mts.1989.11.2.02a00030. https://www.researchgate.net/publicat... Although I first learned about it in the Gaceta Matemática of the RSME, the theory of well-formed scales, thanks to Marco Castrillón and Manuel Domínguez. http://gaceta.rsme.es/abrir.php?id=1130 Physics and Music: The Science of Musical Sound (Harvey E. White et. al.) Jaime Madrid Gómez Lemnismath -