Chopin's Prelude #4 (measures 13 - 16)

These measures are a variation of measures 1 - 4. The same chords are used but the voice movement is much faster. This sort of diminution and an auxiliary diminished 7^th of the V degree in measure 16 helps create the climax in measure 18.

In the following example we compare measures 1 - 4 and measures 13 - 16. The lines show how the voice movement is accelerated in measures 13 - 16: