Organistrum

thumb|right|200px|Elders of the Apocalypse playing an organistrum Santiago de Compostela, Spain

The organistrum is an early form of hurdy-gurdy, with a soundbox shaped like an 8 attached to a rectangular extension. Generally considered the ancestor of later hurdy-gurdies, the organistrum differs substantially in that it was played by two individuals: one turned the crank while the other pulled the keys upward to change the musical pitch of the strings. In other examples a player pushed levers forward to create the notes.