Black Angels, 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 " as written on the score. The Latin phrase in tempore belli, in time of war, written into the score by Crumb is a reference to the Vietnam War taking place at the time when Black Angels was composed.
Robert Greenberg has interpreted the "Electric Insects" symbolized by Crumb in Black Angels as representing attack helicopters in military deployment during the Vietnam War.
George Henry Crumb Jr. was an American composer of avant-garde contemporary classical music. Early in his life he rejected the widespread modernist usage of serialism, developing a highly personal musical language which "range[s] in mood from peaceful to nightmarish". Crumb's compositions are known for pushing the limits of technical prowess by way of frequent use of extended techniques. The unusual timbres he employs evoke a surrealist atmosphere which portray emotions of considerable intensity with vast and sometimes haunting soundscapes. His few large-scale works include Echoes of Time and the River (1967), which won the 1968 Pulitzer Prize for Music, and Star-Child (1977), which won the 2001 Grammy Award for Best Contemporary Classical Composition; however, his output consists of mostly music for chamber ensembles or solo instrumentalists. Among his best known compositions are Black Angels (1970), a striking commentary on the Vietnam War for electric string quartet; Ancient Voices of Children (1970) for a mixed chamber ensemble; and Vox Balaenae (1971), a musical evocation of the humpback whale, for electric flute, electric cello, and amplified piano.
Crumb in 2019 attending a performance at Alice Tully Hall in honor of his 90th birthday