7. PHRASE : V inflects | If you say that a person or organization is calling the tune, you mean that they are in a position of power or control in a particular situation.
- Who would then be calling the tune in Parliament?
CF. call the shots and call the tune: Fig. to make the decisions; to decide what is to be done.
- Sally always wants to call the shots, and Mary doesn't like to be bossed around.
- They don't get along well. Sally always wants to call the tune.
- Why do you have to call all the shots?
- Do what you're told. I'll call the shots.
CF. call the shots/tune: to be the person who makes all the important decisions and who has the most power in a situation
.... McGraw-Hill Dictionary of American Idioms and Phrasal Verbs,
Cambridge Idioms Dictionary,