Prelude and Fugue in C-sharp major, BWV 872

The Prelude and Fugue in C major, BWV 872, is a keyboard composition written by Johann Sebastian Bach. It is the third prelude and fugue in the second book of The Well-Tempered Clavier, a series of 48 preludes and fugues in every major and minor key.

Analysis

Prelude

The prelude is in common time and has 50 measures, built upon the characteristic arpeggios similar to the famous C major prelude from the first book of The Well-Tempered Clavier until the fugato.
The arpeggios ends at 25, and the fugato starts, which uses the time signature of. It has three voices.

Fugue

The fugue has three voices and 35 measures. The subject is simply made from notes from the major triad, but has mutated many times throughout the whole fugue.