The essential parts are:

• The group of 20 pipes which produce the sound
• The compressed air generation system
• The transmission system of the mechanical crank movement, that activates both the compressed air generator and the paper roll traction.
• The paper roll holes reading system and the air distribution to the pipes system.
• The punched paper rolls.

 As above mentioned, contrarily to his commercial brothers, the Busker is not equipped with pneumatic valves, but is designad with an air distribution system that delivers directly the compressed air across the holes of the paper roll into the corresponding pipes. 

This precise choice was made to simplify the construction as the valve assembly would require a precision and a skill which would result as a great barrier for the average hobbyst.

 As a counterpart, taking into account that to obtain a minimum sound power from the pipes it is however necessary to send a certain air quantity, it is necessary to act on the hole dimension.

 

Therefore the holes of the Busker paper rolls are bigger (4mm) with respect to those of the organs with pneumatic valves, consequently also the roll becomes larger (14 cm).

Moreover, to obtain a volume equalization for three bass notes, requiring a greater air flow with respect to the other ones, their corresponding holes have a width of 6 mm.

As such, the Busker configures itself with a non standard roll with respect to the various music rolls proposed on the market.

Notwithstanding this, we see that the J.S. Busker became on his own a de facto standard in the catalogue of those offering roll music for crank organs.

Now, to focus its architecture, let's enter into the details.