There are alarm clocks, teddy bears and music boxes you can upload MP3s to or record your own sound and they will play that back on request, usually in very bad quality.

I like the chime sound of classic mechanical music boxes, and so do many children. Most of these use rotating cylinders with little bumps stroking a comb to generate their noise. Some use classic punch tape instead, where holes mean notes. The latter you can kind of program yourself.

It would be much cooler, though, if you could just transmit a standard MIDI file from your computer via USB or Bluetooth to the music box, the bumps on the cylinder would change accordingly and henceforth generate a different melody.

I’d also take an USB xylophone or carillon, but have seen both baked on You Tube with some Arduino magic. (If only I didn’t have two left hands an no patience.)
-- Crissov, Jan 08 2013

USB xylophone http://vimeo.com/46571145
[Crissov, Jan 08 2013]

USB carillon http://blip.tv/mech...er-carillon-1529062
or bell tower [Crissov, Jan 08 2013]

Not yet modified for USB... Cement_20Truck_20Mu...Ice_20Cream_20Maker
[normzone, Jan 08 2013]

symphonion to MIDI http://createdigita...res-images-details/
solution for opposite direction [Crissov, Jan 14 2013]

[+] The problem you might have is that you'd be stuck with a fixed length for the song.
-- FlyingToaster, Jan 08 2013


[+] For realistic emulation, the music box could be powered by a wind-up connected to a small generator, The speed of playing could decrease as the voltage lowers. No batteries indeed, so could last many years as mechanical music boxes.
-- piluso, Jan 09 2013


// fixed length for the song //

I imagined that the cylinder would be update dynamically, so this wouldn't be an issue. The bumps could be raised an instant before they reach the comb and lowered after they pass.
-- scad mientist, Jan 09 2013


//The problem you might have is that you'd be stuck with a fixed length for the song.//

Change the speed of the drum to match the length of the song. Very slow for long songs, very fast for short.
-- doctorremulac3, Jan 11 2013



random, halfbakery