There is no evidence that there is significant demand for keyboards larger than the conventional 6.5 inch octave keyboard, which is indeed ‘large’ by historical standards.
While there are some Caucasian men who have difficulty fitting their fingers between the black keys, there are possible solutions in relation to design of the black keys. Black key shape and size is not standardised.
Men with thick fingers do not necessarily have a very large hand span, so may not want to lose some of their available reach by having a keyboard with even wider white keys.
Pianists worldwide – even including many concert pianists – overwhelmingly complain about ‘small hands’ not ‘large hands’.
