The original small-orchestra version of Pegasus was written for the Sinfonia Viva Orchestra of England as a thank-you to their conductor Nicholas Kok. Using the birth of Pegasus — the winged horse emerging from the blood of Medusa and ascending to the heavens — was inspired by the name of the Rolls Royce jet engine called Pegasus.

Pegasus was expanded to a full-orchestra version for the West Hollywood Symphony, which gave the American premiere in April 2001.