To play it by ear is to decide as you go rather than plan ahead. Let us play it by ear.
It admits there is no plan and makes that sound like a choice. It comes from playing music without written notes, which is exactly the same skill.
1phraseplay it by earTo decide as you go rather than plan ahead.
“We will play it by ear and see what the weather does.”
play it by ear is a phrase.
Practised in Idioms