Atone cluster is a large group of neighboring notes played together in an aggressive, percussive sound. henry cowell played his signature tone clusters on a. knobbed gongs. b. electronic instruments. c. the piano. d. tape.

The correct answer is C) the piano.

Henry Cowell was an American pianist during the early to mid 20th century. Cowell was known for the use of new and revolutionary ideas in the music industry. He spread these ideas to other musicians and went overseas to Europe multiple times to share his expertise with other musicians.