I don't think practicing piano or performing alone is a creative endeavour unless you are either adding to or mutating the piece you are playing, or are using y

I don't think practicing piano or performing alone is a creative endeavour unless you are either adding to or mutating the piece you are playing, or are using your piano skills to compose new pieces. "Making" art, as another commentor put it, is the productive action, not studying to make art. The distinction is different for visual arts and music.