(born New York City, 1951) American video and sound installation artist who has worked in the vanguard of electronic media since the early 1970s. Viola participated in David Tudor's workshop on Rainforest IV in 1973 and became a founding member of the group Composers Inside Electronics, which grew out of the workshop. His work treats sound as a vital component of video and incorporates new technologies and formats (large screen, videotape, film, site-specific work) and diverse sources from travels to the South Pacific and the Himalayas.