Pulse Train

for flute, clarinet, violin, viola, cello, percussion, piano
duration: 7′
written for the Aspen Contemporary Ensemble; Syd Hodkinson, conductor

Program Notes

As I was drafting ideas for a new chamber piece and searching for a concept, my mother mentioned that my father, a former physicist, was credited in 1995 as an author of US Patent #5389931 describing radar signal processing. Reading the abstract reminded me why I chose not to pursue his path:

“A conical scan radar system (10) provides return pulses (30) to an A/D converter (38) from which a shaped pulse train is received and stored in a FIFO memory (40). The stored pulse train is then passed through first and second finite impulse response filters (42,44) for achieving sampling rate reduction prior to rendering via a programmable signal processor (64) of target detection identification and tracking.”

Though I had absolutely no idea what any of this meant, the phrase “pulse train” struck me as a possible title for the piece. Upon further research, I learned that a pulse train (or pulse wave) is a non sinusoidal waveform similar to a square wave, with extremely sharp changes in amplitude and contour. Because I had about three sketches that were very different texturally and harmonically, this concept fit my sketches perfectly–the jagged contour of the pulse train could provide cohesion for a piece built upon contrast within the same tempo. Therefore, shifts between disparate textures occur frequently and without warning. Ironically, it was not until after I had finished composing that I realized the piece largely has the character of a locomotive.

Premiere: August 19, 2010. Harris Hall, Aspen Music Festival and School
Aspen Contemporary Ensemble; Sydney Hodkinson, conductor