Leonardo da Vinci invented the viola organista, a bowed keyboard instrument designed to let one musician sustain several notes.
Leonardo drew several versions of the instrument in his notebooks, with the best-known designs dating from the late fifteenth and early sixteenth centuries. Pressing keys was intended to bring rotating wheels or bowing mechanisms into contact with strings, producing sound in a way that combined features of a keyboard and a string instrument.
Unlike a harpsichord, which plucks strings, the viola organista was designed to bow them. Unlike a conventional viola, it could be played from a keyboard. Leonardo never produced a known completed instrument, so the surviving evidence consists chiefly of drawings and descriptions.
Modern makers have built reconstructions based on those drawings, but the instruments vary because Leonardo’s designs were not a single finalized specification. The invention reveals his interest in applying mechanical engineering to musical expression.