Measures 12 to 19

On measures 12 to 15 the motive disappears. Measures 12 to 13 are based on the Gb major seventh chord from measure 11. A short melody is presented below the chord:

Nicole Muller, piano - Piano Society

This melody is the development of the previously presented and interrupted melody from measures 6 and 7. Once again it is difficult to find the tonic of the scale. It would be a Gb Lydian mode if we consider the Gb as tonic:

In measures 14 and 15 Debussy rests over a C dominant chord with an augmented eleventh (F#) and a minor thirteenth (Ab) (note the rhythm of the motive on the bass):

Nicole Muller, piano - Piano Society

This section is based on the whole tone scale:

This chord takes us to a varied recapitulation in measure 16:

Nicole Muller, piano - Piano Society

The variation consists of a short melodic motive on the bass (G - Ab - Bb) and the melody in the upper voice (E - Ab ...). The constant use of the A flat (except the last A that is an A natural) suggests the second mode of the F minor melodic scale: