Really, really good game! But.. it needs some improvements, for example:
1)The background(for what concern paintings and,not always,music) has to be consistent with the year in the game; so with the contemporary trends and movements(for example, when the gamer discover the impressionism, the background could change with a Renoir painting).
2)Somehow this is connected with the first point. I had the feeling that some artistic movements where advantaged. And this could be historically correct for some reason (and only in certain contexts), but i would try to conceptually expand the contexts as the game goes on(like the art saloon, the cafè,ecc.), in order to make the game itself more coherent with the history of art and valorize every movement.
3)Implement the dialogues with the other artists.
This is what i would actually change. Keep up the good work!