I always thought a hurdy-gurdy was an instrument in a box on wheels, used by street musicians (maybe with a dancing monkey).
The Wikipedia page offers this note:
In the eighteenth century the term hurdy-gurdy was also applied to a small, portable "barrel organ" (a cranked box instrument with a number of organ pipes, a bellows and a barrel with pins that rotated and programmed the tunes) that was frequently played by poor buskers (street musicians). Barrel organs require only the turning of the crank to play; the music is coded by pinned barrels, perforated paper rolls, and more recently by electronic modules.[citation needed] The French call the barrel organ the Orgue de Barbarie ("Barbary organ"), and the Germans Drehorgel ("turned organ"), instead of Drehleier ("turning lyre").
And here's a picture of a barrel organ - much closer to what I had in mind...
