One-string, one-HDD musical instrument


The Multichord musical instrument is an acoustic stringed instrument with a single string, constructed from wood, a hard drive, 20-lb monofilament, and assorted electronic components. It was the culmination of a project to build an acoustic instrument capable of playing multiple notes without fretting or manual, time-consuming retuning. The Multichord achieves this by attaching a hard drive read/write head assembly between the resonant string and a tensioning spring to adjust the tension of the instrument’s string. Careful adjustment was made to the tension of both the string and the spring with the hard drive head in a neutral, unpowered position to ensure a bipolar application of voltage within the safety ratings of the hard drive’s coil could cause the string to cover a full musical octave. In the end, the Multichord was tuned to a C-major scale (no flats or sharps) running from A at 220Hz through (but not including) A at 440Hz.

[via Hack a Day]


10 thoughts on “One-string, one-HDD musical instrument

  1. Nick says:

    I can think of three things: first, in the video he says C at 440, which you correctly changed to A at 440 (since that is an A note), though I’m not so sure he knows what scale he’s actually playing in that case.

    Second, it doesn’t play one chord, let alone “multi.”

    Third, that string is going to break real fast getting with the tension changing all the time like that.

  2. Anonymous says:

    pretty crappy project; what value does this serve to society?

  3. Nick says:

    Glad to see one of Chris’s projects featured here. I f you would like to see more of his projects, or learn more about him, go to

  4. ionymous says:

    A rubber band over a shoe box sounds better than this. I don’t see any added value here.

  5. says:

    Give a guy a little respect, alright?

    @anonymous, @ionymous Re:sound quality. While Chris’s ”
    Multichord” doesn’t appear to (as currently constructed) have a great musical projection based on the single video that we have all seen, I wouldn’t call the idea dead.

    He does appear to have a piezoelectric mic clipped to the sound hole, but it it clear that its output was not used for the video. After all the work that went into this, he probably didn’t feel like editing the video with a second audio track (instrument line out), and just wanted to get the video up.

    @ the first Nick. I’m sure he means chord as its literal definition “string” as in chordophone, the family of musical instruments including guitars, etc. I don’t have any qualms with the name – to me, taken in context of the project’s design, it says “one string as many strings”.

    The first of any breed of inventions is always extremely primitive but imagine what this idea, when matured, would look like. Self-tuning instruments? Perhaps a future guitar could jump from standard tuning to ‘open G’ by turning a knob?

    At face value, I’m certain a purpose-built string re-tensioner would perform better, but I have to give kudos to making a commonplace component fit the bill.

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My interests include writing, electronics, RPGs, scifi, hackers & hackerspaces, 3D printing, building sets & toys. @johnbaichtal

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