Abscission

"Abscission" is the botanical term for the process by which plants and trees lose their leaves. The trumpet begins the piece with all 12 pitches classes available to perform, while the piano has none. As the piece progresses, the trumpet gradually drops pitch classes which the piano can then articulate. Eventually, the piano has all twelve pitch-classes while the trumpet has none, inverting the opening pc distribution. This process is an abstract, musical representation of abscission, whereby plants and trees lose leaves while the ground accumulates them.