Wikipedia
Organistrum
The organistrum is an early form of hurdy-gurdy. Generally considered the ancestor of all subsequent hurdy-gurdies, the organistrum differs substantially from later instruments 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 melody strings.
Usage examples of "organistrum".
Two persons playing the organistrum, a stringed instrument vibrated by means of a circular bow or wheel, like the hurdy-gurdy.