Spectral Evidence, for percussion and piano, focuses on the stages of sleep and dream memory. “Spectral evidence was a form of evidence, based upon dreams and visions, accepted in court during the Salem Witch Trials. Spectral evidence was typically testimony given that an accused person’s spirit or spectral shape appeared to the witness in a dream while the accused person’s physical body was at another location” (wikipedia). This work is driven by the statistical occurrence of “non-steady-state” brain activity during the different stages of sleep. Brain activity such as Sleep Spindles and K-Complex are mapped to activity through the work. In addition, the “steady-state” brain waves during the different stages of sleep were considered when determining the overall evolution of density in the work.

Spectral Evidence was composed with the aid of GRACE, an algorithmic composition environment, by Taube. Spectral Evidence is an experiment in spectral composition, and is part of the continued experimentation by the composer in mapping the statistical occurrence of gestures over the course of a work. Spectral Evidence was commissioned by percussionist Caleb Herron.