An apparent non-thing, that has nonetheless earned a place in bizarre literature and wikipaedia, the Oracle of the World. Essentially, a writer depicted an organ made out of cats, their tails strung out like piano wires, pulled taut as a key was pressed and eliciting a cry of pain, or note of pain. A cruel and somehow I suspect unpleasing form of music that good sense has prevailed over and as far as we know, never been tried.
The um.. credit (?) belongs to Jean-Baptiste Weckerlin. You can read more here..