The link below is to a video in which a performance is played using an instrument conceived by Leonardo Da Vinci, but only recently actually constructed for real.  That alone would be enough to make it worth checking out.  But the instrument has an absolutely gorgeous sound to boot (Kontakt library in the works, can we hope?).  Yeah, it's probably a bit of a nightmare to maintain, but, wow, what an acheivement.
 
http://www.huffingtonpost.com/2013/11/19/leonardo-da-vinci-viola-organista-pinao_n_4304142.html?utm_hp_ref=arts

It sounds really nice!

It sounds like a mellow synth pad! 

Is it like a hurdy gurdy?

mike_mccue
Is it like a hurdy gurdy?

Probably remotely like one.  However, the tone is clearly more refined and the playing mechanisms significantly more complicated.  But, yeah, there's a rotating wheel with some kind of bow-string material on the rim and when contact with a string is made, sound is produced.