For those of us who have chosen to play the piano regularly but have not chosen to make it a career, it would seem reasonable to label our piano playing a "hobby". But is it one, really?
Here are some definitions of "hobby", taken from various dictionaries:
An activity that you do for pleasure when you are not working
A pursuit outside one's regular occupation engaged in especially for relaxation
A regular activity that is done for enjoyment
An activity that you enjoy doing in your spare time
If this is what a "hobby" is, then I don't think it fits my relationship with playing the piano. Those definitions are much too casual; I often drink a cup of hot cocoa; that fits all the definitions above, but I don't think of it as a hobby at all.
More importantly, I think there are other categories than "work" and "hobby", and that piano playing falls into one such category - at least for me. I also play tennis, and that to me is a hobby, but I can quit tennis for months and then return to it again without issue. Not so with playing the piano; there is no break from that, because it is a necessity to me. I have chosen to make it part of my life, sort of like wearing clothes, or shaving, or filling the tank in my car. It is not vital for my existence, but it is vital for my happiness. It is part of what makes me the person I am.
I can't think of any existing name for that, but there ought to be one. "Way of life" is too grandiose, "predilection" is too weak, "avocation" makes it secondary to a primary job and only works before retirement from the job.
At any rate, piano playing is a choice.
