Sonic Fruit and Veg Machine

As the Welsh “Fire-Break” finished (31/10/20) I’d prepared a project which conformed to all the social distancing regulations whilst still managing to engage as many people as possible regardless of their musical skill or aptitude. I’ve always liked this non-elitist socialist approach towards composition shown by Cornelius Cardew and his contemporaries. This was the third experimental evening this Autumn and unfortunately turns out to be the last for the year due to new regulations on hospitality venues. Our previous event required significant ambulatory movement but its been devised to be undertaken all from your seats. The purpose of this post is to describe the event but also to share the composition and preparation, including design of oscillators, should anyone want to stage the event themselves. So, Ladies & Gentlemen, I give you …..


Theme: A soundscape generated by interpreting the digestive tract activity of five friends who are vegans.

Players: The audience

Required Skills: Read a pictorial “score”. Place fruit & vegetables on prongs roughly at the indicated time. No musical skills required, this is a process of observing simple but timely instructions.

Size: Four groups of four people to a table. 2 sound sculptors.

Equipment: Four “Dronios”; custom built oscillators that change pitch when fruit and veg are applied (see below). Bells to indicate time. Sound mixer, PA and some electronic effects.

The Vegan Score

No-one had ever played a “Dronio” before and they defy notation, so a conventional score would be useless. Consequently I contacted four households who I knew to be vegans and asked them to scope out their fruit and vegetable intake for a typical day and at what time. I then built a pictorial timeline:

Each “Dronio” represented a household and so the indicated fruit & veg is to be placed on the instrument at the appropriate time. As there were three oscillators per Dronio and four Dronios in total, there were 12 drones so changes to just one tended to be small and the output becomes a group effort. Time was kept by one of the sound-sculptors (me) and indicated by sounding a bell and holding up cards to show the time. This was totally arbitrary – I followed my stomach so to speak.

You can download the score for free here (Sonic Fruit and Veg Machine). Please feel free to use it for your own production.


Each table had a “Dronio” which was then sent to a mixer which was able to send to one of two effect channels. These could be manipulated by “Sound Sculptors” and then sent to the main PA

Dronio development

A “Dronio” is a custom built electronic unit which consists of 3 pair of prongs on the top, each corresponding to a squarewave oscllator; squarewave to give maximum harmonics for the sound sculptors to play with. As a piece of food is placed on the top it changes the resistance in the timing circuit of the oscillator and the frequency changes. The three oscillators are combined through a summing amplifier and output through the jack socket on the side of the box.

Finished “Dronio” with a test potato in place


If anyone with electronic skills wants to build their own “Dronios” full details are enclosed in the files below:


It worked! 18 players and various onlookers had a bizarre and entertaining evening in a world that is short of artistic activity at the moment. A special shout out to the group of 20 somethings who “just went down the pub” and were thoroughly engaged and delighted with their own input. “If this had been staged in Bristol and known it was on we would have paid to get in!”. Also another couple near the fireplace who were completely surprised, mystified and pleased they’d engaged in something so different.

If anyone wants to put this on elsewhere then get in touch and I’d be pleased to collaborate. I still have four Dronio’s doing nothing at the moment and would be happy to lend them out.

Anyway, here’s a rough old video of the evening’s proceedings:

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