- Edwin M. Ripin
- , revised by John Koster
One that enables the performer readily to play music in a different key from that in which it is written, generally for the purpose of enabling the music to sound at a different pitch (usually to accommodate a keyboard accompaniment to the fixed or preferred pitch of other instruments or singers) or to permit the playing of music in a ‘difficult’ key while using the fingering of an ‘easy’ key. There are two principal ways in which this may be accomplished. In one, the keyboard simply slides sideways relative to the jacks, hammers, stickers, strings etc. of the instrument of which it is a part. In the other method, there are two keyboards which are displaced from each other by a certain fixed interval.
The latter method is known principally from the standard two-manual harpsichords made by the Ruckers family in the late 16th-century and the first half of the 17th. In these, the upper keyboard sounds at normal pitch, while the lower keyboard, which plays the same strings as the upper keyboard, is positioned so that it sounds a fourth lower. The lower-manual ...