Prelude No. 15 in Db Major by Frédéric Chopin

Prelude no. 15 in Db major is in compound ternary form. The following table shows the structure (click the letters to see the excerpts):

Db major A 3 parts section		A 4 measure phrase that is repeated (measures 1-8)
		Three phrases of 4 measures each in Ab minor and Bb minor (9-19)
		First measures are repeated. The section ends over the dominant chord to prepare section B (20-27)
C# minor A 2 part section		Group of 4 phrases of 4 measure each that is repeated (28-59)
C# minor A 2 part section		Two phrases of 4 measures each that repeat with a small variation to prepare the recapitulation (60-75)
Db major No subdivisions	Section A first phrase followed by a small coda (76)

A dominant pedal (Ab in Db major, G# in C# minor) is present during most of the prelude.