In my experience, the really good musicians are also good people who don't get stuck up about boundaries and definitions of types of music, etc. They may play in their own "style" but that doesn't prevent them liking other music.

The good ones like to share, educate, and learn all the time. They may get tired of playing or hearing some of the old "standards", time and time again, but if they are played or sung honestly or well, or with a different twist, they are pretty open to participation.