Pondering about … Janko, actually all Janko does is equalizing the Kbd in key size and heights (!) The pattern itself is not really equal, because only chromatically placed keys, regular in size and heights would yield a truly equal Kbd pattern.
(Sadly, our hand are unable to span chords with the black keys in the same row.)

Thus, my idea is creating the next best thing to the latter:
Instead of a Janko pattern, where some of the keys of any scale are in another row, let’s might as well stick to the ordinary (zebra) piano pattern we already know, but with the huge difference, by equalizing its keys in in size and heights!! (I.e. no narrow sticking out black keys! All white and black kwys equal in size and heights!!)

Result: This would offer the same advantage Janko offers (added advantage: without the need to relearn a new Kbd pattern). I cannot see any disadvantage, can you?

Also, I reason that longish pentagonal buttons might even be better, because they offer room for a second (or several) Kbd(s) in parallel.
D/l my pattern here: http://rapidshare.com/files/223061450/Zebra_Button_Kbd.jpg.html
Please, let me know what you think of it. Thx, Johannes K. Drinda from Chile