The crank of the organ has 2 functions:

1 - It turns a roller which causes the music card to advance. On the 36 hole Odin organ, the card is crushed by a press.

On the 27 reed model, it slides into a drive mechanism.

2 –   It turns a crankshaft connected to one or several bellows inside the case of the organ.

When the music card is pressed, or when the drive mechanism is engaged, it presses against the spikes

The spikes are connected to the valves by springs.

Each valve corresponds to a pipe or a reed (depending on the type of organ). When a spike meets a hole in the musical card, the valve opens, allowing air through to the pipe or reed.