- sing a different tune
- to change your story, attitude, or opinionThe same imagery recurs in various phrases.Thus the musical British politician Edward Heath, not especially renowned for the consistency of his policies, was said to sing from a different song sheet:Indeed, a former prime minister, Edward Heath (who was subsequently to sing from a different song sheet), admonished the government to press ahead with democratic reform. (Patten, 1998, writing about Hong Kong)Those said to sing off the same hymn sheet or to sing the same tune are taking the same line or expressing publicly the same opinion.
How not to say what you mean: A dictionary of euphemisms. R. W. Holder. 2014.