If anyone’s wondering why you would do this as a musician.

Obviously you can visualize how you’d play something, but skipping the obvious things…

You can do music theory analysis on pieces you’re interested on, it’s something that helps later with improvisation or composition

It also helps you understand the style you’re studying a bit more, it takes a lot of effort although with years of experience you can probably analyze a piece of music fairly fast, and on the bus even