Digitally Fabricated Instruments

A group of digitally fabricated instruments LtoR: bullroarer, tri-bumbler, bumbler, whistle stack, whistle tree, whistle

This project uses generative design techniques to create novel instruments. The designs are executed with digital fabrication methods including 3D printing and laser engraving/cutting.

I’ve used these instruments in two original compositions. The first, Crow Chases Red-tailed Hawk, is scored for a soloist using the newly-created instruments along with live electronics.

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The second, Birds of Passage in an Egg-shaped World, is scored for 6 or more musicians performing exclusively with the newly-created instruments. Birds of Passage in an Egg-shaped World was premiered at the California Institute of the Arts under the direction of Tim Feeney.

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Instruments used in Birds of Passage… LtoR: bumbler, cross bumbler, bullroarer, tri-bumbler, bumbler with wax paper, whistle, whistle tree, whistle stack, whistle

There are 3 main types of instruments: Bullroarers, Bumblers and Whistles.

Bullroarers are the simplest instruments to create. These are laser cut from wood. You can experiment with different sizes for different tones—larger shapes generally create lower and slightly louder sounds.

Bumblers use rubber bands as free reeds to create a humming or buzzing sound. The basic Bumbler design allows the user to specify the number of rubber bands. Bumblers come in a other varieties such as the tri-bumbler and the cross bumbler. The instruments are laser cut from wood. Adding wax paper to the instruments changes the timbre and volume.

Whistles are all built from a basic module with a side slit that acts as a tone hole. The basic whistle module can be combined to create conglomerate instruments such as whistle stacks and whistle trees. This design is adapted from a film can whistle I first encountered from a description by Bart Hopkins of Experimental Musical Instruments. The design Hopkins described was made by cutting a hole in a canister used to hold 35mm film. The version here has attachment bars on the top and bottom so it can be chained with other instruments.

The basic whistle module can be combined to create conglomerate instruments such as whistle stacks and whistle trees.

Whistle stacks generate a tower of whistles all tuned in relation to the base whistle.

Whistle trees are ‘grown’ using a recursive branching algorithm. This creates a group of whistles that branch out from a central trunk. Each whistle is tuned in relation to the base whistle.

VAWT whistles use vertical axis wind turbine (VAWT) foils to encourage a more periodic rotation of the whistle. The VAWT code was adapted from the work of Zippitybamba and Patrick Gaston.

(My first experiments in this area were with woodblocks or temple blocks. I haven’t used these designs in performance or compositions, but you can find more info here.)

How can you use these instruments?

  1. Make your own set of instruments
    • Download the STL and SVG files and 3D print or laser cut your own instruments
  2. Customize the instruments
    • Modify the OpenSCAD code to create your own versions of the instruments
  3. Perform with the instruments
    • Download the score for Birds of Passage in an Egg-Shaped World to perform with the instruments.
    • Download the score and Max patch for Crow Chases Red-tailed Hawk
    • Or create your own score/improvisation using the instruments

About the OpenSCAD files

OpenSCAD is an open-source 3D modeling program. Download OpenSCAD and find out more at

Visit the Bullroarers, Bumblers and Whistles pages to download the OpenSCAD files and modify the designs to create your own versions of the instruments. The designs are parameterized so you can easily change salient aspects such as tunings, numbers of tones created by the whistle stacks and whistle trees, size, etc. Or create an entirely new design based on the code.

Materials needed

  • Laser cutter/engraver (for bullroarers and bumblers)
  • 3D printer (for whistles)
  • safety glasses
  • string
  • swivels
  • scissors
  • sandpaper (for bullroarers and bumblers)
  • rubber bands (for bumblers)
  • wax paper (for bumblers)

This project was supported by an ORED Small Grant from the University of Alabama titled New Music for Digitally Fabricated Instruments.