How about this for a fabulously wacky instrument ? It's a Couenophone, also known as a goofus. Whilst at first glance it just looks like a saxophone take a closer look at all the buttons. Those buttons are layed out as two octaves of a piano style keyboard - this means I might be able to play such an instrument. This particular model is currently up for sale, unfortunately the price of £750 means I'll never find out if I can play such a wacky instrument.