Like and Unlike

Hello.
Could you take a look at these sentences and tell me if I got their meanings right?

1. He isn't into music like John (John is into music).
2. He isn't into music like John is (John is into music).
3. He isn't into music, like John (John isn't into music).
4. He isn't into music, unlike John (John is into music).

And which of the following does sentence #5 mean?
5. He doesn't play the piano like John.

A. John doesn't play the piano, and he doesn't, either.
B. John plays the piano, but he doesn't.
C. He plays the piano differently than John does.

Thank you in advance for any help.