Cocktail Party Fact: The “tone clusters” in the second movement of this concerto, in which the flat of the hand is used to play an entire octave of notes at once, are a device Bela Bartok learned from the music of the American composer Henry Cowell.

Commitment Factor: About 27 minutes.

Vital Statistics: Modern Period. Not quite as percussive and radical as the First Concerto, but still out there.

What to Listen For: The only players who get a break in the incredibly demanding first movement are the strings, who don’t have to pick up their bows until the second movement. In the hushed opening of the second movement, the strings play a series of ghostly chords based on the interval of the fifth. (Charles Ives used the same procedure in his Central Park in the Dark.) After some hostile dialogue between piano and kettledrums, the manic trio section bursts in with those tone clusters, and lots of other amazing tricks besides. The third movement is a rondo in which increasingly violent restatements of the rondo theme alternate with material from the first movement. This concerto resides near, if not at, the very pinnacle of early 20th century modernism.