String piano

This article is about piano playing techniques. For the Leonardo da Vinci instrument, see Viola organista.
Cover of Henry Cowell: Piano Music, recorded in 1963, with Cowell demonstrating the longitudinal sweeping technique

String piano is a term coined by American composer-theorist Henry Cowell (1897–1965) to collectively describe pianistic extended techniques in which sound is produced by direct manipulation of the strings, instead of or in addition to striking the piano's keys. Pioneered by Cowell in the 1920s, such techniques are now often called upon in the works of avant-garde classical music composers.