Well, you are part of the community. If you get value from playing piano or chess then you've provided value to the community.

I think there are two reasons to have chosen community here. Firstly you could chose to do thinks for the benefit of someone else, if that's what you want. Secondly it gets you to think about the externalities that exist.

I guess the person you are replying to thought it was obvious that a person is a member of the groups that they are a member of.