Welcome to English in a Minute.
If you listen to American English, you probably have heard this phrase: "Play it by ear."
What does it mean? let's find out by listening to an American English conversation.
A: Hey, what do you want to do this weekend?
B: I don't know. We could see a movie or have dinner. Why don't we play it by ear?
"Play it by ear" means you aren't going to make a firm plan, but will decide what to do as you go along.
This idiom has a musical meaning too. When you don't have the written music for a song, but you play the notes that you think you've heard, you "play it by ear."
So when you are in a situation where you make a plan as you go, you're "playing it by ear".
And that's English in a Minute.