Taking for granted that a normal keyboard is perpendicular to the floor, I wonder what effect would a keyboard have that is not. Some compact pianos (such as Baldwins) have this. The infamous Geyer, I have found out, seems to copy Baldwin in some ways. I have taken measurements and this is what I have found out: At the front, the bottom of the keys is 68,5cm above ground. At the back, where it connects to the hammers, it is 65,5. The length of the keys is 32cm. My guess is that the eye, seeing a keyboard at an angle, perceives it as being shorter than it actually is and thia affects the way one plays. (At least when I studied analytical geometry I learnt that seen from an angle a line seems shorter than it actually is, being perceived as a point when 90 degrees is reached.) I used to own a compact Baldwin, then rented one for a time and now I have this Geyer (I hope to swap next month) and I remember playing much better when I used a Bechstein, a Bachmann and a Roesler, each of which had normal keyboards.