Refers to Pyotr Ilyich Tchaikovsky's "Overture to 1812 in E Flat Major" Op. 49. It is a very famous piece and sometimes said to be one of Tchaikovsky's best works. It is commonly played during the 4th of July because of it's triumph over war sounds.
Listen for 1812 Overture during the 4th of July, you're bound to hear it sometime.
Song about the war between the Russians and the French that ended in 1812 with the French freezing to death in their camps during the Russian winter (adding to the old stereotype, the Russians use two guidlines in wars, Burn everything or let them freeze) This song was hated by its writer (he was paid a lot of money to write it) It is often hated by performers, due to long monotonous passages, and is hated by many audiences for the same reason, the only plausibly good thing about this song is the finale, it involves cannons and a very loud brass section.
Flute Player: My GOD! our band is playing 1812 overture this spring, it sucks!
Trumpet Player: Yeah, but the ending makes it all worth it.