We've seen some pretty cool digital 'orchestras' over the years - the Toa Mata Band, and the Floppy Organ are just 2 examples. There's something deeply satisfying about having an Arduino control things to make music. Neil Mendoza has taken this a step further and make a slightly dangerous orchestra out of kitchen knives.
He bought 16 knives from a dollar stone, and crafted up 6 machines to make different sounds, including banging, clanging, scraping and running high electrical current through them. And what ironic piece of music was used to demonstrate it? Stayin' Alive by the Bee Gees of course!
The music was arranged in Logic X, sequencing the arrangement in MIDI. A USB-MIDI converter outputs the sound from Logic, and the Arduino reads the MIDI data via a MIDI socket. The machines use a variety of solenoids and actuators to control the knives, as well as a 12,000V neon sign transformer to create a visible electric current.
Obviously, this is quite a dangerous project, and we don't recommend you try this at home, but if you really want, you can grab all the source code from his GitHub project page.