This was in the park where I usually walk my dog this morning:
There is not, in the normal course of things, a brightly painted piano in the park. It is no longer there, vanished back to wherever such things manifest from.
I like to imagine that, as it is played, the colors pour in great splashes of paint, on the ground. That bubbles of notes - cerulean and yellow, viridian and white - float into the sky. A symphony of color.
Then, when the song is over, the colors fade with the echoes, leaving grass and stone and tree unmarked. Unless you sing, just under your breath, the right song.