Jankó keyboard
The Jankó keyboard is a musical keyboard layout for a piano designed by Paul von Jankó, a Hungarian pianist and engineer, in 1882. It was designed to overcome two limitations on the traditional piano keyboard: the large-scale geometry of the keys (stretching beyond a ninth, or even an octave, can be difficult or impossible for pianists with small hands), and the fact that each scale has to be fingered differently. Instead of a single row, the Jankó keyboard has an array of keys consisting of two interleaved manuals with three touch-points for every key lever, making six rows of keys. Each vertical column of three keys is a semitone away from the neighboring ones, which are in the alternate rows. Thus within each row the interval from one note to the next is a whole step. This key layout results in each chord and scale having the same shape on the keyboard with the same fingerings regardless of key, so there is no change in geometry when transposing music. Furthermore, the use of multiple rows allows the pianist to more naturally follow the contour of their hand and accounts for the different lengths of the fingers. The configuration retains the