Fantasia on an Ostinato is based on a famous repetitive passage by Ludwig van Beethoven (Symphony No.7, second movement). This music is unique in Beethoven's output because of a relentless ostinato that continues, unvaried except for a long crescendo and added accompanimental voices, for over four minutes. Beethoven's near-minimalistic use of his material and my own desire to write a piece in which the performer is responsible for decisions concerning the durations of repeated patterns led to my first experiment in minimalist techniques.
I approached this task with mixed feelings about the contemporary phenomenon known as minimalism, for while I admired its emphasis on attractive textures and its occasional ability to achieve a hypnotic quality (not unlike some late Beethoven), I did not care for what I found were its excessive repetition, its lack of architecture, and its overall emotional sterility.
In Fantasia on an Ostinato, I attempted to combine the attractive aspects of minimalism with convincing structure and emotional expression. My method was to parallel the binary form of the Beethoven Seventh Symphony ostinato by dividing the Fantasia into two parts. The first explores the rhythmic elements of the ostinato as well as the harmonic implications of its first half. The second part develops and extends the ostinato's second half, transforming its pungent major-minor descent into a chain of harmonies over which a series of patterns grows continually more ornate. This climaxes in a return of the obsessive Beethoven rhythm and, finally, the appearance of the Beethoven theme itself.
Fantasia on an Ostinato was initially conceived as a solo piano work for the 1985 Van Cliburn International Piano Competition. In that version I left the decisions concerning repetition of repeated patterns in the central section to the competitors, so that judges and audiences might hear their varied viewpoints as to the building of the climax of a musical structure. The orchestral realization, however, is completely notated, and thus completely controlled. In addition, certain sections have been expanded, both in texture and duration, especially the central section that leads to what is now a considerably more developed climax.
– John Corigliano