March to a different drummer/drum - Idioms by The Free Dictionary
march to a different drummer/drum
march to (the beat of) a different drummer
Fig. to believe in a different set of principles. John is marching to a different drummer, and he doesn't associate with us anymore. Since Sally started marching to the beat of a different drummer, she has had a lot of great new ideas.
march to (the beat of) a different ˈdrummer/ˈdrum (also march to a different ˈtune less frequent) behave in a different way from other people; have different attitudes or ideas: She was a gifted and original artist who marched to a different drummer.