Orbital Variations for solo cello by Shawn Crouch, composer

Orbital Variations for solo cello is a multiple theme and variations that explores the harmonic gravitational pull towards a central pitch, the pitch D.

C G Bb D F# A

The composition begins on D but quickly moves away in the first variation to the distance of two perfect fifths away to the pitch C. As the piece progresses the gravitational forces of D pull the composition back to its original center culminating in the final coda and moving through all six pitch centers on its trajectory back to the pitch D.

There are seven themes that are first heard in the opening thematic area and are explored in the proceeding six variations. Each variation contains a different pitch center that by the final variation are combined to create a collective theme themselves.

Throughout the composition there is an acceleration and deceleration of the musical line. Generally speaking as the music encounters the pitch center of each variation the energy and pacing accelerates as it approaches and decelerates as it leaves the pitch center. This is similar to orbital mechanics where a gravitational slingshot occurs when a spacecraft uses the gravity of a planet to accelerate.

With each variation the thematic material becomes increasingly entangled in the previous variation; the line where one variation ends and the next begins becomes blurred, until the last variation when all of the themes become intertwined, and all of the pitch centers are recapitulated emerging as a new theme.