Watercolor Study in Db Major No. 1

In this variation I let two tones from outside the Db minor triad, C5 and D5, enter the phrase as red and orange. They sit among the chord tones as tensions, small warm fields against the prevailing blue-green and blue. The chord holds the frame, and the outsiders give the phrase its warmth."
This could anchor to Prop. 29 (Aperture Play): the slack where diffraction happens.