If I'd ever imagined Snape playing an instrument, it'd be a violin, or maybe a cello, because of its capacity for expression, in a man who is fairly stunted when it comes to using his own physical body to express.
I love how relaxed and contemplative Harry seems, and how patient and focused on his task Snape is. Truly a mentor and his student here. It's a beautiful drawing (Harry's bow hand is perfect, and the shadows on the wall are lovely). I must confess I've cougghhmadethismydesktopcouugh looked at this at least a dozen times.
Nailed that genre and your prompts, and given us a beautiful picture here. So very well done!