Knurl, an on-the-fly music instrument, is a creation of the composer and cellist Rafaele Andrade that allows a musician to perform live an integrative and creative practice. Knurl has a format of a cello, it runs and modifies music while projecting code and graphical visualization into the performance circle. In addition, it becomes a platform for communication with the audience, since they also obtain the control of musical creative choices during its performance. A machine listening system offers advice to the performer to facilitate the management of present and future actions.

The instrument is designed with some ethical values of our current scene, bringing an unstandard vision of creative music production into political, technological and ambiental discussions. This project brings open source practices, sustainable 3d printing, creative coding and sustainable energy sources into the hands of a diverse team composed by local artists, designers, scientists and programmers. The integration of those practices results in a product-model of music practice that stimulates shareability of music control between its audience, the accessibility to a diverse range of possible customization triggers, tasks and voice control of electronic sounds for music composition, and its exploration and accessibility of unconventional tuning systems into today’s standard music practice.

In the past year of development constructing and refining Knurl has became the product of an artistic research organization (Knurl Lab[2]) that brings creative coding into the hardware of music instrument making, dialoguing with political, ambiental and tech and other issues that our music world has been facing (climate change,globalization, etc.).

The design of the "Knurl" is registered on Patamu with license no 147729 (CC BY-NC-SA 4.0) Copyrights: Rafaele Andrade


  1. Knurl is hybrid, this is one of the biggest features if you're investigating the crossovers of electroacoustic music, whereas the speakers are attached into an acoustic body
  2. It is design to be played as a baroque cello or lirone, with the possibility to rotate and using other range of pitches offered by a scordatura that corresponds to the whole harmonic circle
  3. Knurl has 16 strings, which 4 of them are resonate strings with hipshots (immediate tuning changing)
  4. Being aware of sustainability and circular economy, the instrument can be produced with recycled PETG, biodegrable Material or with carbon fiber composites. For isolation, we use recycled TPU.


  1. The ability to charge the instrument by solar energy
  2. The instrument can be manipulated by its audiences or other performers by an interactive web based platform
  3. A oled screen is attached to the bow, in other to show the console to the performer
  4. New investigations with AR (Augmented reality) including typographic methods for scores are being tested with augment reality patches


  1. The instrument involve a diverse range of aesthetics and compositional methods
  2. The performer can use and create its own system, redefine buttons and program its rules during its performance
  3. The instrument can be transcript by a score_based software, allowing the performer to reproduce a performance exactly like its original version
  4. Experiments with Machine Learning are applied in one of the modes of performance


The design it is a story of Rafaele's musical experience. That relates thoughts about composition, cello practice, performance, sustainability, conducting, live coding and Sonology in one single experience: her cello practice. The conventional issues of a standard instrumental practice were reinvented into new values of the XXI century, such as shareability, customization, Acessibility, Machine control and diversity of music styles. This offers a new array of possibilities that radically expands the instrument's interactivity with its environment. With Knurl, musical instruments can be also practiced by its audience and collaborators.