The progressive change of the colors also represents the slow change to higher notes on the piano. The reflection of a source of sunlight in the piano keys and the back of the picture display the strong colors (that may get out of control) that hit you as you see a rainbow.
Harm Goslink Cooper is a musician and artist who combines his two passions to produce whimsical yet functional musical instruments. His homemade piano is his most ambitious effort yet. The rustic wood case and colorful keys look great together! See more of his instruments (and listen to his terrific songs) at Goslink.