"Amoroso", played on a gothic harp:
http://www.asni.net/amoroso!.wav To answer your question, yes, that is one single instrument. I've been mentioning bray strings; they're the vibrating strings providing the drone sound. The hurdy-gurdy gets its distinctive, bagpipe-like sound from them. The medievals thought it was great and so do I. During my abortive attempt to learn to play guitar, I found I liked the noise of strings buzzing against the frets, even though I later found out it was considered an "error" in playing.
Screw that! Bray strings have been described by musician Melissa the Loud (look her up) as the reason they didn't need electric guitars in the middle ages. Apparently even though gothic harps don't have loud voices due to their narrow soundboxes, they can be heard over other instruments because of the bray strings. Of course, if a harp's competition is a lute, that's not hard.