Joaquim Alves Gaspar, Lisboa, Portugal
The Portuguese poet Fernando Pessoa wrote that Newton's binomial theorem was as beautiful as the Venus de Milo.
I would like to add another masterpiece to the pair: Bach's Chromatic Fantasy and Fugue: 
I can't resist putting an alternative: Beethoven's last piano sonata: 
... and yet another one (so beautiful that hurts, or maybe I'm becoming soft with age): Chopin's Étude in c-sharp minor: