just strumbled across this:
a similar concept could be applied to create a new kind of midibox controller
cite:
Be your own DJ in a very colorful way! The BeatBearing Sequencer is an exciting, entertaining and innovative way to rock to your own beat. Move the ballbearings on the transparent grid and you change the beat.
Lots of musicians use a computer to create beats and sequence mixes, but I wanted something to use with other musicians or in a live performance, plus have a unique and cool look.
The idea of the BeatBearing sequencer was born.
What is the BeatBearing? It’s a computer interface overlaid with the grid pattern of metal washers and ball bearings. The plastic transparent case is what transforms the sequencer into its uber-coolness. The system is controlled by an Arduino microcontroller, and the screen is an old computer monitor cradled in a milk crate.