ELI5, why are the musical notes represented by letters in some places (C-D-E-F-G-A-B), but in others by their sound (do-re-mi-fa-sol-la-si-do) ?

Question

I’m from Mexico and the way I learned the musical notes was by their sound, however some friends from other places learned the notes with letters.

In: Other

Answer 1

Do re mi etc is not as awkward to sing as c d e f g a b. But the letters are used for musical notation, which is pretty complex if you really get into it, so it makes sense they picked the first letters of the alphabet for that.