Extended Harmony

The use of ninths, elevenths and thirteen chords was common in Debussy's music. Follows some examples of these types of chords in this prelude.

Measure 9, Db with 7^th, 9^th and 11^th:

This chord has a dominant of Gb function.

Measure 12, Gb with 9^th, 11^th:

Measure 17, Ab minor with 9^th and Db minor with 9^th:

Measure 18, Bb major with 7^th, 9^th y 11^th:

This chord has a dominant of Eb function.

Additional resources about extended chords:

Ninth chords, teoría's Online Reference
Eleventh and Thirteenth chords, teoría's Online Reference