MIDI-Gurdy, MIDI-Gurdy, MIDI-Gurdy Man

The hurdy gurdy is the perfect musical instrument. It’s an instrument with a crank, and a mechanical wonderment of drone strings and weird chromatic keyboards. No other musical instrument combines the sweet drone of bagpipes with the aural experience of an eight-year-old attempting to play Hot Cross Buns on a poorly tuned violin.

Now, the hurdy gurdy is going digital. The Digi-Gurdy is [XenonJohn]’s entry into this year’s Hackaday Prize, and it’s exactly what it says on the tin: it’s a musical instrument that drones on and on, with keys plunking out a melody.

If you’re not familiar with a hurdy gurdy, this video is a varily good introduction. It’s a box with somewhere between four and six strings mounted on the outside. The strings vibrate by means of a wooden wheel powered by a crank. There’s a keyboard of sorts along the body of the instrument that ‘fret’ a single string providing the melody; all the other strings are drone strings that sound continuously. I think it was in, like, a Led Zeppelin video, man.

While it’s a slightly complicated build to make an analog hurdy gurdy, delving into the digital domain is easy: [XenonJohn] is building a hurdy gurdy that simply outputs MIDI commands with some buttons and a Teensy 3.6 microcontroller. The parts are 3D printed, and since this hurdy gurdy is completely digital, you can change the tuning of the drone strings without actually tuning them. Awesome.

19 thoughts on “MIDI-Gurdy, MIDI-Gurdy, MIDI-Gurdy Man

  1. “No other musical instrument combines the sweet drone of bagpipes with the aural experience of an eight-year-old attempting to play Hot Cross Buns on a poorly tuned violin.”

    That honestly made me laugh out loud. :P

  2. No crank ? I am slightly disappointed that there is no rotary encoder to drive the tunes. Maybe in a future iteration?
    Still, this is a great idea as practice instruments do not exist for the hurdy.

    Looking forward to seeing the development.

    1. Since the crank is used to give rhythm to the original instrument – playing the dog and also “pumping” the base strings – this is only about 1/4 of the real deal.

      1. Could this not be simulated digitally? The other charm of the instrument is that it can be tuned for modal music rather like a ‘honky tonk’ piano. Can this be simulated with midi and a digital synthesizer?

        1. Yes, it can! Search for MidiGurdy on the web and you’ll find my (commercial) project of an electronic hurdy-gurdy that aims to be as close to the acoustic original as possible. While the hardware is not open (yet), all software and sounds are available on GitHub already. It’s main purpose is to be used as a practice instrument so you can practice quietly without disturbing your spouse and neighbours, but some people have already used it on stage as well.

    2. Without much reasoning I feel like a rotary encoder would be the wrong way to go about getting the crank information. I’d go for a wheel and an optical mouse sensor. Perhaps with a home position sensor somewhere in the wheel to keep it calibrated, but that would only be for fancy things.

      1. Very early on I experimented with mouse sensors for the MidiGurdy, but they had problems at higher cranking speeds. And having absolute angle information is quite useful to do visualisations of the right hand technique. So I’m now using a 14bit rotary hall sensor, with a diametrically magetized magnet on the end of the shaft. Working really well… Although the usable resolution is more like 12bit… Still, definitely enough, even at lower speeds.

  3. I’m really curious about hurdy gurdistry, I’d really like to give it a go some day but I have to wonder how anyone gets into it when it has such a high price barrier to entry. I have a plethora of musical instruments which I love, but I didn’t get into any of them by immediately spending thousands.

    1. Well, there are a few gurdies for less than 1000€, the TPV by Joel Traunecker. And then there’s the NerdyGurdy by Jaap Brand, another open source/hardware project. It’s 350€ for a kit, 700 € assembled. And definitely useable as a beginner gurdy!

  4. The hurdy gurdy could be played with a slide instead of the keys. If I put a dynamo for 12volt power on my self sustaining guitar it would be cranked for the sound output, even though it’s electronic but with a string. Now this article makes me want to add keys to what I have already. It would be monophonic (one note) but still have the Digitech stereo output.

    A dead nickel battery drill is ready to have a crank chucked into it and make DC power, I need to experiment.

  5. Thanks for the comments. For completeness, bearing in mind the title of the piece, there is a device out there called a MIDI-Gurdy which is nothing to do with my efforts in this area. It is a very close digital approximation to a real instrument with pressure sensitive keys allowing you to bend notes as on a guitar, a working crank and many other features. It is quite expensive but will always be in tune when you power it up before a concert. In contrast my Digi-Gurdy is an attempt to produce something low cost and portable that you can practice melody parts with.
    Not all HG’s are roughly made folk instruments by the way, do an image search for: weichselbaumer hurdy gurdy carbon and you will see what I mean.
    I am still learning about MIDI. If anyone knows how I can add an extra sound (the rhythm section buzzing sound) to the existing open-source soundfont file I am using to generate everything else, this would be very helpful.

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