Pyotr Ilyich Tchaikovsky's Pas de Deux ('The Nutcracker')
Tchaikovsky was a Russian composer in the Romantic period. He received many recognition because of his works.
His works was also used in romantic and tragic plays until this day. Plays like: The Nutcracker, Romeo and Juliet, etc.

I mostly watch the live orchestra playing this, also the ballet. The music is so moving in a way that it makes you feel what the characters are feeling in the play. It really is a perfect match in the part of the play in The Nutcracker.