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Neurohedron: A Nonlinear Sequencer Interface

2010 January 5

The Neurohedron

Read the full NIME Conference Paper!

Traditional music sequencers are designed fundamentally around predictability and repetition, and these are powerful elements that make them so ubiquitous.  More modern approaches to algorithmic composition heavily involve unpredictability and randomness that is then (sometimes) tamed and manipulated by the composer, resulting in a nonlinear compositional and performative process.

The Neurohedron is a novel music instrument and modal software controller that I conceived of as a nonlinear sequencer.  The simplest traditional sequencers may employ eight steps that return to the first step after reaching the last step; in contrast, the Neurohedron is a three dimensional sequencer with twelve nodes arranged as a dodecahedron.  With this structure, there is no clear or de facto path that the progression from one node to the next may take, unlike the linear and prescribed nature of a traditional sequencer.

The Neurohedron

Each face on the device is both a touch-switch that sends input triggers to software as well as an electroluminescent panel that displays feedback from the software.  While the platform could be used in a huge variety of ways, my first inclination was to use the inputs as stimuli in a 12-node neural network, where each face is connected in a graph to the 5 faces adjacent to it.  Each of the edges between these faces is then weighted between 0 and 1, and the progression from one face to another follows the highest weighted edges.

Each node (face) in the network is then mapped to a MIDI note.  These mappings are described by a variety of musical modes.  Thus, a sequence on the Neurohedron will send patterns of MIDI notes to a synthesizer platform (Ableton Live, in this case).  This platform is wide open, of course, so anything could be triggered in principal.

Here’s a video overview of the Neurohedron in action:

Here’s a demonstration of the old software (need to post a new video):

The interface is multi-modal, meaning that there are 5 states the interface can be in that determine what it does:

  • Input: Pressing a face triggers an input stimulus to the neural network at that node
  • Stop: Holding a face down stops any circuits that encounter that node
  • Live-play: Sends MIDI notes pursuant to that face’s current mode-mapping
  • (Musical) Mode: Changes the mode-mapping of the network
  • Randomize: Randomizes all of the neural network’s weights

Here’s a little demo of Matt Boyle & I playing the Neurohedron in live-play mode.

Process & Production

The Neurohedron’s hardware consists of:

  • Plexi & aluminum skeleton
  • Laser-etched faces
    • Momentary switches
    • EL panels
  • Logic Board
    • ATMEGA328PU Microcontroller
    • 2x shift-in registers
    • 2x shift-out registers
    • FTDI USB Interface
  • AC Switching array
    • 12x Optoisolated triac & low-current triac pairs

This video demonstrates the shift-in and -out registers controlling switches and panels:

And this one detailing the AC switching:

Here’s a link to a large version of the Neurohedron for print & publication.

And finally, a gallery of production photos:

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10 Responses
  1. Shortino permalink
    June 18, 2010

    Great stuff! looks (and sounds) awesome! Any chance you’ll posting up the code behind it?

  2. August 27, 2010

    What a coincidence ;D

    We’ve been working on a musical device based on the same
    spatial form – dodecaherdon 😉 and called it Docecaudion 😉
    There are a lot of differences though
    – it’s not a seqencer but live performance instrument based on IR distance sensors
    so it has “analogue” qualities similar to theremin x 12 😉

    Here are the guts:
    we still working on the shell – it’s going to be based on duraluminium skeleton
    and laser-cut HIPS or plexi faces –
    ( but as you can see in the visual it’s going to be mounted a bit differently ).

    You’ve been first to actually produce instrument based on
    dodecahedron but I hope that you believe and understand that our
    project is totally independent and haven’t been “inspired” in any way
    by yours.


    • August 27, 2010

      Wow, it’s beautiful! I’d love to see it in person some time!

  3. September 3, 2010


    I’m glad you like it :)
    There is a chance that we’ll finish manufacturing process this month,
    final proportions of physical object will differ a bit though ( due to
    IR beam spreading the holes needs to be larger ).

    I’ll update you when there are some photos / videos available.
    Oh, and we are going to release Dodecaudion under creative commons and
    open source license :)


Trackbacks and Pingbacks

  1. NIME 2010 « Maiestas
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  3. Create Digital Music » In Photos: Discovering Sound Making, Electronics at Culturefix NYC
  4. Neurohedron is a unique music instrument and modal software controller : Steelberry Clones
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  6. Neurohedron Sequencer – The D12 Music Sequencer – Synthtopia

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