Prelude, Op. 28, No. 4 (Chopin)

Hans von Bülow called the prelude "suffocation", due to its sense of despair.

The treble line (resembling a "pedal point", unusually in the upper voice), constantly goes down chromatically for the entire piece, excluding the climax and measures 9 and 12.

The 8th note ostinato in the bass begins on an inverted E minor chord and continuously descends chromatically with the treble.

At measure 16, the fortissimo marked climax of the piece begins, and ending by returning to the slow, chromatic motif.

The piece makes it way down to the tonic, before aburuptly ending on a German augmented sixth in measure 23.