An attachment for a grand piano has a flexible strip secured on a shaft which is mountable rotatably underneath the strings of the piano. The strip and shaft can be turned by a linkage means terminating in a control knob at the front of the piano. In one position of the strip it is interposed between the hammers and strings to modify the tone of the piano and in a second position it is out of the way of the hammers. The tone can be modified to sound like a harpsichord or it can be muffled completely depending on the material of the strip.