eli5: in music, since there are 12 notes per octave, why are only 7 letters used instead of 12?

Question

eli5: in music, since there are 12 notes per octave, why are only 7 letters used instead of 12?

In: 15

Answer 1

The 12 half steps are an adaption of the fact that a 7 note scale is not created around equal note separations. 7 note scales are different from each other (major vs minor being the two biggest ones), but they are a mix of 5 whole steps and 2 half steps. To make an instrument that can play more than just one scale, a lowest common denominator needed to be found and the 12 half steps work out just right for that.