Today's and yesterday's song of my day has been Prokofiev's Dance of the Knights (also known as "Montagues and Capulets" in his orchestral suites) from the ballet Romeo and Juliet. I've always been at a loss for words to adquately describe this piece. It is moving and stirring in places, triumphant in others, sombre here and abruptly quiet, pensive and nostalgic elsewhere before resurging back to a finale.
It's just utterly breathtaking and I hardly ever get tired of it. Highly recommended.