The 7 note major scale is more-or-less an historical accident: https://en.wikipedia.org/wiki/Musical_system_of_ancient_Greece https://en.wikipedia.org/wiki/Musi

The 7 note major scale is more-or-less an historical accident: https://en.wikipedia.org/wiki/Musical_system_of_ancient_Greece https://en.wikipedia.org/wiki/Musical_system_of_ancient_Gree....