Technical passage from La Rêve
In addition to his music career, Kalkbrenner also had some business success. The hand-guide is a device that Kalkbrenner developed and sold that was used to help to achieve better piano technique. This device is a modification of a similar device called the chiroplast, which was patented in 1814 by Johann Bernard Logier. The chiroplast was a sliding rail that sat right above the keys of the piano in order to control the wrist position of the user. Kalkbrenner’s hand-guide altered the chiroplast to allow for the thumb to rotate. This device is a testament to the technical and virtuosic writing of Kalkbrenner.