As "Pianomania" gradually reveals, Knüpfer is able to do this so well because he is as much of a crazed perfectionist as the pianists themselves, maybe even more so. Someone who has bad dreams about torn strings and turns off the radio if he hears an ineptly tuned piano on the air, Knüpfer is fully capable of taking a piano apart and putting it back together again. If replacement hammerheads are 0.7 millimeter too narrow — about one-thirty-third of an inch off — he will notice in an instant.