What on earth is this?

What On Earth Is This?

Here is a musical instrument I have never seen before.



It's obviously got a 'drone,' like a bagpipe; and clearly the crank is being used to generate air pressure. Anyone know what this is, or what it's history might be?

UPDATE: Apparently it's called a "hurdy gurdy." The drone is right, but those keys that look like valves aren't releasing air pressure; the wheel is moving against strings that the keys are modulating (except the 'drone strings'). I've seen the words "hurdy gurdy" before, but not the instrument!



This tune is the "horse brawl" (Branle des chevaux).