https://www.musical-u.com/learn/want-to-play-it-hear-it-first-2/
It may sound like a contradiction, but if you want to create music when you play you must be able to hear the music first – in your head.
This goes doubly if you want to improvise, compose or play by ear!
Hearing what you’ll play consists of two parts:
1.Hear internally what you want to play
2.Know how to bring those sounds out into the world
Let’s look at those two in more detail.