Change (one's) tune disapproving verb phrase informal common
Used to say that someone changes one's attitude, opinion, manner, or stance on something, typically in a way that is more positive or agreeable.
The waiter immediately changed his tune after I gave him a tip.
I'm sure once I give up smoking, she'll change her tune.
After having opposed their marriage, their parents suddenly changed their tune.
To become better
Try to avoid to change something because doing something else could make things worse
people often do irrational or foolish things when they are in love.
To stay out of trouble or avoid doing something wrong
As a person's power increases, his or her sense of morality lessens.
The verb "change" should be conjugated according to its tense.
It has been suggested that a version of this term "sing another song" derives from around 1300 and references to traveling minstrels who modified the wording of their songs to satisfy their present audience. By 1600, the first locution was in use.
If you swallow the bait, you take something that someone offers you, or agree to do something that someone asks you to do without knowing that it is a trick or way of getting something from you.
You can't just do whatever he wants you to do. Don't swallow the bait.