Exactly. Music theory is a programming language for musical composition and performance.

Unlike most languages it's inherently two dimensional because music includes both horizontal (time, rhythm) and vertical pitches (chords/colours, harmony) information.

And - especially important - melody is an element that needs both.

You can't represent the same information with text without losing a lot of important content, which is why toys like Sonic Pi are more limited than they seem.

You can kinda sorta represent the same information on a piano roll, but it's not any easier to read than dots - in some ways harder, because you're not going to see the relationship between a bass line and chords as clearly.

Is it a good programming language? It's quite dense, but not denser than some code idioms. The 2D element is unique, and hard to represent in other ways.

The learning curve is steep, but it's probably as good as it can be given the requirements and constraints.