An action in an acoustic piano is provided which can reproduce the touch and feel of the key depression generated in a normal performance mode even in a silent performance mode. The acoustic piano is capable of being switched between the normal performance mode and the silent performance mode. In the silent performance mode, a rotation lever of a transmission switching mechanism disconnects the hammer operating portion from the key. A load switching mechanism is rotated to lower the tip of a weight lever to abut directly upon the upper face of the key. Then, the weight lever swings up and down corresponding to the key depression of a player, closely reproducing the touch and feel of a conventional acoustic piano.