An instrument is a concrete or abstract tool intended for a purpose other than mechanical work, in particular a refined one.
Musical instruments are devices designed to produce music, frequently by plucking or striking a string or bell or drum surface, or by forcing air to resonate (see wind instruments).
... His most famous role is that of the cranky professor forced to stay immobile because of a broken leg in 1942's The Man Who Came to Dinner[?], which he had performed ...