Fast But Sad/Emotional Piano Songs?

Hey I'm looking for a good piano piece that is a bit sad and emotional but also fast. Like Fantasie Impromptu in C sharp minor, or The river flows in you. I guess I don't actually mean sad but more of like not happy song. I have played piano for 3 years and the difficulty should be at like the same level as Chopin's "Black Keys" etude. I want a sad song because I will be playing Black Keys at a competition and I want to really contrasting pieces.Also I want a clical song.