Cocktail Party Fact: No one has a clue where the nickname came from. It certainly wasn’t Beethoven’s idea.

Commitment Factor: About 40 minutes

Vital Statistics: Classical Period (1809). A big, three-movement concerto with a couple of unique features: there is a grand opening in alteration between solo and orchestra, before the usual lengthy orchestral statement of the main themes. Also, the second and third movements are connected, and played without pause.

What to Listen For: Because Beethoven did not write this work for himself to play (he was too deaf), this is the first classical concerto without a place for a cadenza–the spot towards the end of the first movement where the soloist was expected to tastefully (yeah, sure) improvise something on the main themes. Instead, every note is written out in full. Notice also that the big opening gesture comes back later in the first movement–so it’s more than just a flashy introduction. It has a real dramatic purpose. With its prominent trumpets and drums, this piece is the apotheosis of the grand, “military” concerto.