Cocktail Party Fact: “Leonore” was the original title of Beethoven’s only opera, “Fidelio.”

Commitment Factor: About 13 minutes

Vital Statistics: Classical Period (1806). Originally an overture to the opera, Beethoven detached it for use as an independent concert work.

What to Listen For: There are three “Leonore” overtures in all, and one to “Fidelio.” The first two were actually used with the opera. This one, which shares all the same tunes as “Leonore” Overture No. 2, never made it to stage performance. Beethoven realized that this music was so much more dramatic than anything in the opera that the entire first act would be an anti-climax after it. The off-stage trumpet solo just before the whirlwind coda announced the arrival of the good guys just in time to save Leonore (disguised as an man named Fidelio) and her political prisoner husband.