One of the most vocal critics of abstract expressionism at the time was New York Times art critic John Canaday. Meyer Schapiro and Leo Steinberg along with Clement Greenberg and Harold Rosenberg were important art historians of the post-war era who voiced support for abstract expressionism.
Keyboards should be of appropriate size and key-spacing to accommodate most users. Generally, the horizontal spacing between the centers of two keys should be 0.71-0.75 inches (18-19 mm) and the vertical spacing should be between 0.71-0.82 inches (18-21 mm) (Figure 9).
In 1908 Bosendorfer extended the range down to C below bottom A on their large Imperial Concert Grand, which has eight octaves. The lowest note is C below the usual A, up to the top C, 97 keys in all. The piano is 9 feet 6 inches long Width: 5'9, Waght net: 1.255 lb. The standard keyboard of today is 88 notes, A to C, seven and a quarter octaves.