change tune

change (one's) tune (to start saying something different about a subject or situation, or to start behaving in a different way; to adopt a different intention or opinion || to become less confident or boastful) - запеть по-другому, запеть на другой лад; ~сменить пластинку

Example 1: He soon changed his tune when he saw how angry I was.

Example 2: The question is, will the president change his tune on taxes?

Example 3: If the price of a barrel of oil goes down, he'll change his tune.

Related vocabulary:
[change tack]
[shift gears]
change one's attitude,
change one's mind
[about face]
изменения, конъюнктура, перемены