George Henry Crumb or George Henry Jr. Crumb (born October 24, 1929) is an American composer of modern classical and avant-garde music. He is known as an explorer of unusual timbres, alternative forms of notation, and extended instrumental and vocal techniques, which obtain vivid sonorities. Examples include seagull effect for the cello (e.g. Vox Balaenae), metallic vibrato for the piano (e.g. Five Pieces for Piano), and using a mallet to play the strings of a double bass (e.g. Madrigals, Book I), among numerous others. Crumb's most renowned works include Ancient Voices of Children (1970), Black Angels (1971), and Makrokosmos III (1974).