Why do the call it music "theory"

Question

what's with the theory? Music theory is just the way they "think" music works?

Answer 1

In a music “theory” class, you don’t necessarily play any music. Music theory is about how music works – how many beats in a measure, how to read time signatures, etc. In another type of music class, you probably learn how to play music or sing as well as learning a little bit of music theory.

So to answer your question, music theory refers to how music (beats, notes, stuff like that) works. The term “music” is a little more general.