Honestly, if this wasn't a rule, it should be. The rule is: listen. The first rule of music is to listen.

You cannot create anything with your instrument if you cannot listen. Hear what's happening around you, hear the music inside your mind, listen to how the other musicians are playing around you, listen to how your audience wants to be entertained.
Listening is the key.

If you listen well enough, you actually get to play less. That's a good thing! The goal is not to over play, but only play what's needed. What's the minimum amount of contribution you can make that creates the most value? In tech, we call this the minimum viable product (MVP), but in music we simply say "leave space."

Listening is the key to a noise-free life.

If you listen to what's happening around you, and really listen - don't listen/judge, you will know better where to focus your time and attention.

Phone ringing, news is blaring, dog is barking, kid just got home, the neighbors kids are running around - so much stimulus. Listening allows us to pin point the thing that matters. It's invites us to choose to spend time greeting and being with our kid.

Listening is the key to being a great leader.

So many leaders come to their teams with ideas of how things should be now that they're in charge. A great listener listens to their team and asks the team to suggest the next move - less is more.

Listening is the key.
... to de-cluttering the world around you and only doing the most essential work.