I mean, ear training is often a course in music programs.
Ear Training 1
Ear Training 1 is all about learning how to accurately recognize, imagine, remember, and notate musical sounds, while gaining the ability to read music notation.online.berklee.edu
Oh so it is a thing? The way they make it seem in the manga is that every musician should be able to understand notes, which makes Lucky come across as a total idiot for not knowing these basics.