The concept for Christopher Deane’s classic marimba quartet Vespertine Formations was to explore ways of creating a sense of sustain on four marimbas through extensive use of stretto and imitation. Rather than approaching an ensemble such as this in a traditional choral configuration of soprano, alto, tenor and bass, this piece focuses on keeping most of the musical activity within the same register. All four voices serve as equal members of one collective image. Vespertine Formations is dedicated to Harold Jones who was the professor of percussion at East Carolina University for many years. The motivation for this work comes from a phenomenon in nature. It is a common sight to see huge flocks of birds performing amazing aerial maneuvers in the evening sky over North Texas especially in the Autumn. The ornitholigical sky forms witnessed during one particular sunset in Fall of 2001 served as an undeniable point of inspiration during the compositional process for this piece. The wing motions of so many birds suggested the texture of constant sixteenth notes. As the brilliant orange sunset diminished to dusk, the birds settled into trees around the campus. The fantastic choreography created by this flock of birds and the natural chronology of events guided the structure and form of this piece.