What is Play It By Ear?
1.
-To let things go as they may.
-It is usually said when a person who is asked a question is not quite sure as to what to answer with.
Shirley: What are you doing tonight Bob?
Bob: Oh, I don't know...I'll just play it by ear.
2.
to do something by feel and instinct rather than with a plan, to improvise
I think I will play it by ear since I have so much time.
See
3.
Letting you down politely, when you ask someone to do something and they want to do something, just not with you, they will say they're going to "play it by ear".
"What do you want to do tonight?"
"I don't know; I think I'll just play it by ear."
See