The most serious problem about your post #723, AB, is that it offers me too much temptation to head to the gutter with jokes about playing with <vulgar synonym for "cat">. Can't react to it like I would have during my time playing music on Bourbon Street.
Actually, that's a joke on my part that fell flat because you didn't recognize the name. M C Escher was an artist known for drawing all sorts of optical illusions and "alternation of attention" cases.