- Edwin M. Ripin
- , revised by John Koster
With reference to keyboard instruments, a term used to describe either the amount of force required to depress a key (‘touch weight’) or the distance that a key may be depressed (‘touch depth’ or ‘key dip’). Thus a keyboard may be said to have a heavy or a light touch, as well as a deep or a shallow touch. In harpsichords, the touch weight necessary to depress a key and cause two or three sets of jacks to pluck their strings is approximately 60 grams and the touch depth is about 7 mm. In modern concert grand pianos, the force necessary to depress a key to sound pianissimo is about 100 grams and the touch depth is about 10 mm. In 18th-century grand pianos, the corresponding figures are about 35 grams and 6 mm. In clavichords, the touch weight may be less than 10 grams. In organs, the weight and the depth of the touch vary considerably and depend in part on whether the action is electric or mechanical. For further information, see M. Cole, ...