10. Ondes Martenot
The martenot is perhaps the most unique instrument on this list. It’s also the most coveted by hardcore collectors. Invented in 1928, it sounds kind of like the theremin and kind of like a violin, but has multiple tube speakers and a unique way of playing, with a ribbon attached to a ring. While the original remains a collector’s item, a couple companies are building remakes that might make the instrument easier to find. In the meantime, we’ll have to be satisfied with people like Radiohead’s Jonny Greenwood making tunes with this unique instrument.