Pictorial imagery is rarely absent from Schwantner’s music. His imaginative and evocative titles attest to his keen interest in extramusical inspiration. A Sudden Rainbow is cast in a one-movement symmetrical arch form, a form that takes its cue from a natural phenomenon, as the composer explains:
I found the analogy between the developing musical structures and nature’s rainbow appealing and endlessly engaging. The luminescence and prismatic beauty of a rainbow, always a dazzling visual phenomenon, proved to be an alluring and seductive stimulus for me throughout the composition’s evolution.
A rainbow contains the pure colors of the visible spectrum in consecutive bands; it is formed in the sky by the refraction, reflection and dispersion of the sun’s rays in falling rain or mist. In a somewhat analogous fashion, the music often unfolds in stratified layers of orchestra color. Elements of musical continuity, contrast and development as well as other aspects of organization are shaped by the balance of timbral and spatial forces at play in the work.
In addition to the sonic tapestry of the winds, brass, and strings, the piano and celesta, harp and percussion often join collectively to form an expanded instrumental ensemble which produces a profusion of unusually rich and vivid sonorities and textures. This orchestral aggregate comprises one of the principal coloristic strata emphasized throughout much of the work. At times, specific musical ideas are projected within the orchestral fabric so as to create ‘echoes’ and ‘double images’ which act as a kind of musical correlate to the phenomena of reflection and refraction found in rainbows.
The opening, upward-sweeping gesture, presented by the winds and percussion, contains a collection of eight pitches which function as the primary source for the melodic, harmonic, timbral, and textural ideas that are generated and developed in the work.
A Sudden Rainbow was a Meet-the-Composer Residency Commission during Schwantner’s tenure as composer-in-residence with the Saint Louis Symphony. The premiere took place on 1 February 1986 under the baton of Leonard Slatkin. A Sudden Rainbow was subsequently awarded Third Prize in the Kennedy Center Friedheim Awards (1986), then was nominated for a Grammy in 1987 as ‘Best Classical Composition’.
from notes by Laurie Shulman © 2005