A major figure in 20th-century music,  Morton Feldman was a pioneer of indeterminate music, a development associated with the experimental New York School of composers also including John CageChristian Wolff, and Earle Brown. Feldman’s works are characterized by notational innovations that he developed to create his characteristic sound: rhythms that seem to be free and floating; pitch shadings that seem softly unfocused; a generally quiet and slowly evolving music; recurring asymmetric patterns. His later works, after 1977, also begin to explore extremes of duration.

Born in Queens in 1926, Feldman found a kindred spirit in John Cage, whom he met in 1950 at a Carnegie Hall performance of Anton Webern’s Symphony, which Cage and Feldman loved but to which the audience responded antagonistically.

Coptic Light (1986) is brief by late-Feldman standards, just under a half-hour. It was premièred by the New York Philharmonic in 1985, just two years before Feldman’s death. The texture is dense throughout, to the point that details are impossible to grasp. Within each section of the orchestra, pitches are echoed back and forth in varying, off-centered rhythmic placements. Feldman was an avid collector of Middle Eastern rugs, and frequently based his compositional techniques on their asymmetrical patterns. In his own program notes, he recounts that Coptic Light was inspired by ancient Coptic textiles on display at the Louvre. He also noted Sibelius’s comment that the primary difference between writing for orchestra and piano is that the orchestra has no pedal. In Coptic Light, Feldman attempted to write for orchestra with the pedal. His stated goal, similar to Cage’s, was to remove intention from composition; in effect, he wanted the sounds to compose themselves. Feldman took great pains over his scores to keep them from sounding man-made. They lack traditional themes and development. Instead, they are rigorous explorations of timbre. Phrases are carefully put together so as to avoid any sense of definite contour. Some of his late works take several hours to play. Even the shorter ones seem entrancingly, hypnotically long because they seem to have no beginning, middle, or end – they are like cross-sections of clouds.

Tilson Thomas was an acquaintance of Feldman’s, and his conducting is very compelling.