Introducing...

One of the most annoying things ever invented by man (or at least I think it is), the metronome.

It's supposed to help pianists to maintain a certain speed and tempo, but as far as I'm concerned, all that loud metallic "ting!"s are a pain to the ears, and I can never keep track of 2 sounds at once, especially if one of the sounds is a never-ending stream of "ting!"s.

Plus, you have to wind it up by hand, like some clockwork alarm clock decades ago. I don't know about the newer models, but the ancient one I have (made of metal and plastic instead of wood like the one in the pic) requires you to do so. Bleh.

Well, there you have it.