change one's tune, to
sing another tune
To change one's opinion, behavior, or attitude, especially suddenly or abruptly. He never used to support that political candidate, but he's singing another tune all of a sudden. I used to be very cynical about the world, but ever since surviving that car wreck, I've been singing another tune! They'll be singing another tune after they see what we've come up with.
Farlex Dictionary of Idioms. © 2015 Farlex, Inc, all rights reserved.
change someone's tune
to change the manner of a person, usually from bad to good, or from rude to pleasant. The teller was most unpleasant until she learned that I'm a bank director. Then she changed her tune. "I will help change your tune by fining you $150," said the judge to the rude defendant.
McGraw-Hill Dictionary of American Idioms and Phrasal Verbs. © 2002 by The McGraw-Hill Companies, Inc.
change one's tune
Also, sing another or a different tune . Reverse one's views or behavior, switch sides, as in When she realized she was talking to the bank president, she quickly changed her tune, or I bet Dan will sing a different tune when he finds out what the salary is. A version of this term, sing another song, dates from about 1300, and it has been theorized that it alludes to itinerant minstrels who changed the words of their songs to please their current audience. The first locution was already in use by 1600. Also see dance to another tune.
The American Heritage® Dictionary of Idioms by Christine Ammer. Copyright © 2003, 1997 by The Christine Ammer 1992 Trust. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.
change (one's) tune
To alter one's approach or attitude.
American Heritage® Dictionary of the English Language, Fifth Edition. Copyright © 2016 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.
change one's tune, to
To reverse one’s views, change one’s mind, switch sides in a controversy. The analogy is very old; John Gower wrote, ca. 1394, “Now schalt thou singe an other song,” and the actual phrase, “change your tune,” appears in a ballad about Robin Hood (one of the Child ballads) from about 1600. And a character in Samuel Beckett’s novel, The Unnameable (1953), says, “I have my faults, but changing my tune is not one of them.”
See also: change
The Dictionary of Clichés by Christine Ammer Copyright © 2013 by Christine Ammer