Paul von Janko was born in western Hungary in 1856. He was trained as a mathematician and became a musician and engineer, studying under physiologist and physicist Hermann von Helmholtz.
In 1882, he patented a new form of keyboard layout, designed to allow the player to cover a wider span of notes with each hand and to make all keys equally easy to play. Janko's keyboard drew upon earlier designs by Conrad Henfling (1708), Johann Rohleder (1791) and William Lunn (1843).
He used short narrow keys akin to buttons, and stacked them up to form six tiers. The notes were arranged in whole-tone intervals. The first tier, the third and the fifth play a whole-tone scale beginning from C.
The secound, fourth and sixth tiers play a whole-tone scale beginning from C#.
The shape and fingering of a given scale or chord is the same in any key and the octave span is reduced to 5" as opposed to 6-1/2" on a normal piano. In 1886, RW Kurka incorporated a
Janko keyboard into a piano, and Paul von Janko himself demonstrated it in Vienna, playing works by Liszt, Schubert, and Chopin.