Black Angels (Crumb)

Black Angels (Edition Peters, New York, no. 66304, copyright 1971), subtitled "Thirteen Images from the Dark Land", is a work for "electric string quartet" by the American avant-garde composer George Crumb. It was composed over the course of a year and is dated "Friday the Thirteenth, March 1970 (in tempore belli)" as written on the score. Crumb is very interested in numerology and numerically structured the piece around 13 and 7. The piece is notable for its unconventional instrumentation, which calls for electric string instruments, crystal glasses, and two suspended tam-tam gongs.