Music literacy is like having a map in your head instead of using GPS.
I like having maps in my head; so I use map apps for navigation in three ways.
First is if I’m starting in an unfamiliar place: I use it until I get to a familiar landmark, and then I turn it off and navigate home using my memory.
Second is if I’m ending at an unfamiliar place; I’ll look at the map before I start, and then I’ll ignore it until I get to the part of the route I’ve never taken before. (I’ll often say something like, “I’m good for the first 20 minutes.”)
Third is if it’s a completely new route, with no familiar map in my head. Then I’m using it the entire time. (Say, I’m visiting family in Chicago.)
I’ve noticed that many people use GPS navigation even on routes they know well; for me, that’s anathema to my goal, which is to be able to picture the map in my head at all times and use the map only for support. Even in Chicago, if I’m there for a few days, I’m always moving away from the GPS and into the map in my head. Using that internal map is more flexible, more durable, and often more reliable.
Developing your music literacy is like building a map in your head. The more musically literate you are, the more accurately you can interpret, predict, and react to the music around you.
Simultaneously, the more you get your nose out of the score (“GPS”) with memorization, the more you can be in the moment and sensitive to what’s happening around you.
Always be separating yourself from the GPS. Always be building your music literacy and separating yourself from the score.