Proportional chromatic piano keyboard - in which relative key positions correspond to sonic ranges and with short black key between each adjacent pair of long white keys

摘要

As in a conventional piano keyboard, keys are grouped into two types a) long (or white) keys (1) and b) short (or black) keys (2). The centre of each black key coincides with the geometric centre of separator (4) of each adjacent white key. The spatial disposition of the keys is chosen in direct proportion to the corresponding sonic intervals. In this way, a rapid execution of key depressions is possible, without the need for a third key row. The black keys are each 7.5 mm broad and the base and 5.5 mm at the top.