There are professional pianists that play classical music and are fairly casual (in their approach to classical music). There are amateurs that are quite serious, and this can come in many forms: perhaps they play concerts or competitions that they take quite seriously, or maybe they don't play concerts at all but they dedicate a significant amount of their life to understanding the music and playing it well. And there are a lot of semi-professional pianists who make a part of their living playing piano. And where do piano teachers fit into this?