be in tune
1. To have the proper musical pitch. People don't realize how hard it is to be in tune when you can't hear yourself singing!
2. To be in agreement with someone or something. I'm sure she feels the same way I do because we're always in tune.
be ˌin/ˌout of ˈtune (with somebody/something)
1 be on/not on the right musical note: They were both singing out of tune.
2 be in/not in agreement with somebody/something; be/not be happy or comfortable with somebody/something: He’s out of tune with modern ideas about education.I don’t like London — I just don’t feel in tune with city life.