Could someone out there please tell me what the "average" or most common keytop angle (w.r. to horizontal) is on pianos? And in what direction (clockwise from the left, or counterclockwise from the left)? I think I just read that uprights are angled CCW from left (i.e., a marble on key rolls away from player) and grands are angled CW from left (a marble on keytop would roll onto the player). Are any pianos' keys, new or old, nominally horizontal? Thanks very much for any help here.

Rick

I've noticed that most verticals do have keys that angle down to the back, some angle quite a bit. My Baldwin M grand also angles down at the back. As to average angles - el if fry know.

Sorry I can't help.
I've lost my marbles.