In our years here on Hackaday, we’ve seen our fair share of musical hacks. They even have their own category! (Pro Tip – you can find it under the drop down menu in the Categories section). But this one takes the cake. [Andrew Lee] is a student at New York University who had a task of creating a project for his physical computing 
class. In about 60 days time; he went from dinner napkin sketch to working project. The project is quite interesting – he’s made an instrument that plays music as you move your head.
It works as you would expect. An accelerometer in the user’s headphones feed data to an arduino. There are four (3D printed of course) buttons that are used to select the the type of audio being played. The operation goes as such:
- Press button.
- Bang head.
[Andrew] speaks of a particular satisfaction of hearing the music play in sync with the rhythm of head movement. Be sure to check out the video below to see the Nod Bang in action.
A great start. I can immediately see that always having to nod to drive the beat will get old pretty fast, but an easy upgrade would be to use nods to set the beat (like tap timing that already exists in many music apps). With the beat set, the head would then be free to add embellishments, emphasis, extra beats, etc.
Additional accelerometers could harness other motions (sideways, head turn) as additional control parameters.
Rock on!
Could also detect an arpeggio beat from the head nod (while holding down a button) and then use that to trigger the sounds instead of the head nod. kind of like tapping out a rhythm but keeping your hands free,
1: Build a dozen of these, equip a whole dance troupe with them. Sum their outputs into the venue’s PA system.
2: ???
3: Profit!
Needs a metal edition.
The style of music could be controlled by the ferocity of the head nod.
A gentle nod would provide elevator music through to full full bodied head banging for metal.
The biggest advantage for me is that I would always be nodding along in time :)
Get rid of the buttons and make different vectors different sounds. When I dance I often bop joints and foot work in a full drum kit way. If I had sensors at all those places I could play away. There are shoes that have been set up to be triggers in midi setups.