Here's an instrument I'd play if I had my life again, the Welsh medieval crwth (pronounced crooth). In this video Cass Meurig, one of the leading revivalists, speaks eloquently about the instrument's history, music and construction.
Like the hurdy-gurdy, the crwth is a medieval groovebox on which you can play melody, harmony and rhythm. Hearing how it works confirms my hunch that those medieval minstrels were really onto something. I never cease to lament the loss of our own indigenous, improvisatory drone music: at its pinnacle I don't doubt it rivalled that of India or the Middle East.
You can listen to more spine-tingling crwth music here.