change one's tune

change one's tune  {v. phr.},  {informal}
To make a change in your story, statement, or claim; change your way of acting.
The man said he was innocent, but when they found the stolen money in his pocket he changed his tune.
Bob was rude to his teacher, but she threatened to tell the principal and he changed his tune.
Categories: rude {informal} {v. phr.}