HELP!! What is this song stuck in my head. The score below is reasonably accurate with the exception that I don't know the original key, and the time signature could be 3/8 rather than 3/4. It's late classical/early romantic, likely from a piano sonata, and likely a third movement. My first guesses are Mozart, Beethoven, Schubert.

@Aaron The harmony seems more Spanish to me. Albeniz, maybe?

@luserdroog Nice thought, but I'm pretty confident of the era. Come to think of it, I think it's a Mendelssohn Song without Words. Hmm... time for some ISMLP hunting.

HOORAY!! Mendelssohn "Song without Words", Op. 19, No. 2.

@Aaron I'm glad you found it. I would have recognized it, but also not known the piece. I hate when that happens, but it's such a relief when I find out what the piece is.