“The instrument sports a number of unusual features, like a banked fingerboard that fights strain by reducing supination in a player’s left arm. But what truly draws the eye—and drops the jaw—is the viola’s off-kilter layout: It has been stretched on the diagonal to some 20 inches to maximize the vibrating surface area. Because it has also been shortened from top to bottom, it feels like a ¾-size viola to the player’s left hand.”