The Baryton, or "Viola di Bardone", is an instrument from 18th century, with bowed strings and an extra-set of strings in the back of the neck. These strings have two functions : they can resonate as sympathetic strings or be plucked with the thumb. The instrument is rarely played now, largely because of it's extreme difficulty. Very interesting video by Roland Hutchinson on Eriq Koontz's channel https://www.youtube.com/watch?v=QZApJANZjl0 #rareandstrangeinstruments | Rare And Strange Instrument