The story

My son built this instrument for his 8th grade music class using a Target box and a Sweetwater box, an old guitar string, some Lego pieces, and a lot of hot glue. The project was specifically designed for Earth Day 2023, using recycled or found materials lying around the house.

Changing the pitch of the original instrument involves moving a cardboard slide up and down, after tightening the string. The Lego pieces, including a worm gear and crank, control tension on the string. It’s not easy to play live, so we created this instrument. Each note uses 4 round robin samples. Velocity varies quite a bit in a charming, low fi way. The higher octave goes above what it’s capable of doing live.

Playing it reminds me of my son, and it reminds me to keep trying to save the planet. I absolutely love it.

Short demo at


Reviews for One String Cardboard Slide Guitar

Leave a review to let others know what you thought of the instrument!

  • Very fun

    Has a somewhat dulcimer sound to it, very percussive and the dynamics are good. Sometimes the sound drops out if playing fast, not sure if its just my system, but it doesn't occur on my other decent sampler instruments.
    All in all a very fun and nice sounding instrument. its backstory is incredible as well, telling people you have a cardboard guitar on a track raises eyebrows until they hear it. Effects sound good as well. Try it out, it might be the instrument your track needs!

    Smush25 March 2024
  • Animusic vibes

    Checking this library out, I remembered watching Animusic videos with all those strings and drum sounds. 4 RRs is very nice to have! The range is okay for me, though maybe somebody would say it’s a bit small.

    Filter, reverb and chorus give surprising additional variation, probably due to the sound being plucks compared to something with more sustain. And thought there is indeed variation in volume between different samples, volume is still, in my opinion, very consistent! It definitely adds a good flavor.

    Alas one of the lowest note samples os-46-01.wav seems to be cut short. I just edited the .dspreset file for now to exclude it.

    Given the size, the mellow sound and round robin count, I’m definitely keeping this one.

    lainew05 May 2023