change your tune

change (one's) tune

To change one's attitude, opinion, manner, or stance on something, typically in a way that is more positive or agreeable. The mention of a hefty tip really changed the host's tune, so I think he'll be able to find us a table after all. After I threatened him with no allowance, my son changed his tune and started doing his chores.
See also: change, tune

change your tune

COMMON If someone changes their tune, they express a different opinion about something from the one they had expressed before. Wait till they see you in action. They'll change their tune then. You've changed your tune. You were the one who wanted us to be a family act. Note: You can also talk about someone's change of tune. These comments mark a change of tune from the president.
See also: change, tune