FROM TOUCH TO STRING VIBRATIONS .2. THE MOTION OF THE KEY AND HAMMER

This article describes an experimental study of the motion of the grand piano key and hammer. The motions were registered by means of an optical position measuring system. The measurements include typical key and hammer motions at different dynamic levels and for different types of ''touch.'' Also, the accelerating force on the hammer before release (''let-off''), and the following free motion of the hammer were investigated. Resonances in the hammer were detected and examined by modal analysis. A possible influence of the pianist's touch on the string vibrations via the hammer resonances is discussed.