Hans Luedtke

Hans Luedtke was a German inventor in the field of music.
Biography.
Organist, musicologist and inventor Hans Luedtke developed special Oskalyd extended organs and keyboards that could be used with any desired tone system. Rounded edge hexagonal shaped keys were to be arranged like honeycombs in such a way that intervals would be represented by unique vectors (i.e. a Generalized keyboard). He mentioned tunings with semi-, third-, and quartertones, methods for playing special glissandos, electronic switching between tunings or registers during performances, and he also outlined a notation system analogous to the keyboards and a direct opto-electric recording system.