top of page

Chaos Bells (2021)

Winner of the 'Highly Commended' Award in Best Innovation of a Sound Tool or Technique at the 2021 Sound Of The Year Awards, Chaos Bells is a very large (2 metres wide and tall) instrument that features 20 gesturally performed pendulums. Chaos Bells' unique sound design in which bell sounds can drone and become chaotic is how it gained its name. A staccato (short) tone is produced by striking or tapping the instrument either on the pendulums (to create a clear tone) or the instrument frame (to create a cacophony of tones). Tilting a pendulum produces a drone (sustained tone).


I designed with both artistic and analytical goals in mind during my PhD research into the impact of instrument size on musical performance. As a performer of live electronic music, the commercial instruments available to me are so small that they require performance using only the fingertips. This made me wonder: what does the size of an instrument bring to making music? What kinds of musical experiences are we missing out on by only being offered small digital instruments? There are no commercially available digital musical instruments as large as Chaos Bells. Why are there large acoustic instruments but no large digital instruments?

Chaos Bells' most unique engineering feature is its chaotic drone. How it works: the sound is created when 20 embedded accelerometers excite a modified Karplus-Strong synthesis algorithm. The pendulum tilt angle changes the Karplus-Strong algorithm feedback coefficient, thereby changing the drone decay and timbre. When tilted close to 90 degrees, the feedback coefficient becomes greater than 1 producing an unstable system: the drone grows over time, eventually becoming chaotic and distorted as it is clipped by the digital system, finally disintegrating into broadband noise. The result: synthetic bell drones that can be sweet, nasty or anywhere in between.

The most unique musical feature of Chaos Bells is that it can produce many timbres per tone, whether striking or tilting. Even a millimetre change in pendulum tilt angle affects the drone timbre. And when striking the instrument, the timbre changes depending how hard you strike and whether you, for instance, play with hands, soft mallets or sticks. These timbral variations make the instrument sound alive. Performers utilise these timbral affordances to create music of various styles (from ambient to punk) featuring sounds ranging from saccharine to unhinged. Trained percussionists can create particularly timbrally-rich performances, showing the instrument’s potential for virtuosity.

The instrument has a growing list of artists adopting it to create original performances. To date, 11 musicians have composed original Chaos Bells repertoire. Chaos Bells was used for a research study in which 10 London-based electronic music producers and performers created compositions on the instrument that were broadcast on the Augmented Instruments Lab concert 23 Nov 2021, which you can watch here. Additionally, Kunal Singhal composed an original performance with Chaos Bells that was premiered at The V&A Museum during Digital Design Weekend 2022.

Chaos Bells has been performed and exhibited at:

  • V&A Museum, Digital Design Weekend, 23-25 September 2022

  • CHI 2022, New Orleans USA, 2 May 2022

  • Sonorities Festival, Banana Block Belfast, 8 April 2022

  • Deliaphonic Festival, Drapers Hall Coventry, 6 March 2022

  • Supersonic Festival IWD, Centrala Birmingham, 5 March 2022

  • The Oram Awards Ceremony - Lia Mice performance 9 December 2021

  • Augmented Instruments Lab online concert 23 November 2021 - watch here

  • Chaos Theory online concert, 20 September 2021


Odd Lust performing Chaos Bells at Centrala, Birmingham, 5th of March 2022


Lia Mice in front of Chaos Bells, October 2021. Photo by Lizzie Wilson.

bottom of page