Music Box

Not my Idea.

After being inspired by the work of the swedish musician and hobby engineer martin molin, I decided to build my own version of his «music box». A electrically driven roller pulls a strip of hole-punched paper through a mechanical music box.

Wheel holding the music-strip

Analog MIDI

At first, a «digital version» of the music box was created by recording all individual notes (music-box is hard wired to the key of C-Major) into the DAW of my choice. Then I created a track with MIDI and printed the result on templates. The pattern was then transferred to the deliberate musical strip intended for use with the music-box. A «to-lasercut» script would be a nice side-project for the future ;)

MIDI punched into paper strips

Mechanics

The finished music strip (approx. 3.5 m long) was spooled onto a wooden wheel and passed through the actual music box, which was spusepnded over rubber bands and picked up by a contact microphone, into a feed mechanism made of four stainless steel, steel, rubber-coated rollers. The power was supplied by a speed-controlled 12 V DC motor. I attached a 6.3 audio jack on the back to route the signal into an amplifier / audio interface.

Feeding mechanism

Actual music box

12V in and audio-out

Improvements and Afterlife

While the constructions did what they should, some things are definitely in need of improvement. The signal-to-noise ratio is nowhere near where it should be, and the suspension mechanism is a bit too loose, resulting in a lack of timing precision. That being said, the custom-made music box has been used extensively ever since. It is just a very authentic recording of the bell sound of a music box.