Abstract: A damper action for an upright piano that comprises a springed tab on the damper lever that “ratchets” or gives way or folds away in one direction and does not in the other, to provide retention when the spring tab passes by the longitudinal ridge on the sostenuto rod in one direction and non-retention when the spring tab passes by the longitudinal ridge on the sostenuto rod the other direction. The ratchet aspect of the spring tab uses tension from the damper spring and does not require a separate spring to apply tension to yield the ratchet effect.

Abstract: A piano keyboard apparatus has an action assembly that includes a four bar linkage having four pivotably connected bars including a whippen pivotably connected to a repetition lever. An articulated jack has a lower link pivotably connected to an upper link and the lower link is pivotably connected to the whippen.