Hurdy gurdy

A hurdy gurdy is a stringed musical instrument. It consists of several strings arranged such that they can all be vibrated by a rotating wheel covered with rosin[?]. This method of producing sound is similar to string instruments such as the violin; but because the hurdy gurdy produces several notes, a melody accompanied by chords made by "drone strings", its sound is perhaps more comparable to that of bagpipes.

The drone strings just produce sounds at fixed pitches, while the other strings are played by a key mechanism which stops each string, adjusting its length, and hence the pitch.