A new Luuma release comes out on November 15th 2024: Ffroeds, on the Flaming Pines label.

It's available on Bandcamp: https://flamingpines.bandcamp.com/album/ffroeds

Composed primarily using Chris Kiefer's own invented feedback instruments Ffroeds offers a version of music which emerges from a collaboration with these unruly and unpredictable devices.

Feedback instruments are self-resonating, and the vibrations this causes in the devices themselves lead to strange and sometimes uncontrollable outcomes.

It is this realm between control and chaos which Kiefer, releasing under the name of Luuma, is intent on exploring using his strange and rebellious devices. Across five compositions derived from playing membrane-based, and stringed feedback instruments controlled by joysticks, patches and AI learning Kiefer's work offers a uniquely playful and rather messy take on hi-tech instruments.

"With feedback instruments, they have their own complex behaviours and we can only influence or guide them. They have their own personalities – they can be cantankerous and difficult to play, but also joyful and thrilling," he explains.

In Ffroeds Kiefer places us as listeners firmly in this world of exuberant, and sometimes bad-tempered technologies, and in doing so suggests new ways to share compositional outcomes with an instrument.

I'm going to write some posts about how each individual track was made, starting off now with the first track Nalimass.

Nalimass was made with source material from an instrument I designed, the Nalima. Like all the other instruments used for Ffroeds, it's a feedback instrument (or you could also call it a multistable instrument). The Nalima uses feedback to resonate itself with it's own sound, which can lead to some strange, wonderful and unpredicatable sounds. It's a membrane based instrument; the membrane is stretched PTFE plastic, and there's a custom built transducer that feeds acoustic vibrations into the membrane so it acts a bit like a speaker. The instrument has a drum stick/probe with a contact microphone embedded in the tip. This microphone picks up sound from the membrane, sends it through a box of digital effects, and then through an amplifier into the membrane. This feedback loop creates sound, which changes depending on lots of different factors: the pressure and position of the stick on the membrane, the digital effects, the way which you manipulate the membrane with your other hand, and also whatever was happening in the recent past in the instrument. As you might imagine, this is a complex cocktail, which make the instrument very different from conventional instruments.

To make Nalimass, I did a long recording session with the Nalima. It was early days of exploring the instrument, and I was still trying to get a feel for what it did. I started editing this recording down, to see how it could fit into a piece, but I felt like I wanted to take it a bit further and try something I'd been keen to experiment with: the concatenative synthesiser in FluCoMa. FluCoMa is an amazing library for Max and SuperCollider with all sorts of options for audio synthesis, manipulation and machine listening. It was a great system for concatenative synthesis. This works by taking a database (corpus) of audio, splitting it up into small chucks and then organising it according to some sort of quality (e.g. texture, timing, pitch etc), which gets mapped into a 2D space, with similar sounds close to each other. You can then navigate around this space, and replay the chunks according to how they are organised. I made a corpus from the Nalimass recording, and set up a patch in SuperCollider that would navigate and play sound from around the space, with the navigation controlled algorithmically by audio qualities of the sound in the past new seconds - another feedback system! Just to make things a little more fun, I added in a bunch of dirt and distortion from outboard in the studio and from our mixing desk, and then made a new recording of this feedback system. The system sort of played itself, but I manipulated it live through the mixing desk and outboard. The track is an edited down version of this recording. So there it is - a feedback instrument, used to make a feedback synthesiser, within an analogue electronic feedback loop! Layers within and across layers, rendered out into a static piece of music.

The Musically Embodied Machine Learning project, funded by the UK Arts and Humanities Research Council, is exploring the creative opportunities that arise from building musical instruments with embedded/embodied machine learning.

For more info, take a look at https://users.sussex.ac.uk/~ck84/meml/

The Nalima is part of the TEI 2024 exhibtion, in Cork, Ireland.

The instrument has had a few changes since the previous demo at CHIME - the coil is upgraded to copper/aluminium to circumvent some overheating issues, and the DSP now runs in a control box on a Daisy Patch Submodule.

The paper on the Nalima is here.

This is a open source instrument. The firmware is on github. I will add hardware documentation in the near future.

If you are interested in building or playing a Nalima, please get in touch (info: https://profiles.sussex.ac.uk/p208667-chris-kiefer)

I presented the Nalima at CHIME 2023, along with presentations from Steve Symons and Dimitris Kyriakoudis. There's a brief report here.

This is the abstract:

The Nalima had its first public outing. It melted a bit, but never stopped making noise (cue imminent redesign of voicecoil cooling!)

Introducing uSEQ: a module for livecoding within eurorack. We showed this recently at Bristonica, and here's a video demo.

More info: https://github.com/lnfiniteMonkeys/uSEQ

This is demo i've been working on, the Nalima. It's a feedback / multistable instrument, using a membrane for interaction. I'm going to be demoing this at the CHIME Annual Workshop in December.

These past two weeks, i've been in Scandinavia, at Sound and Music Computing conference in Stockholm, and visiting the Intelligent Instruments Lab in Reykjavik. The project that I presented at SMC was on measuring complexity in time series, using a new technique called Random Projection Complexity (RPC). These are the slides from my presentation:

The paper is here:

Kiefer, C. 2023. Dynamical complexity measurement with random projection: a metric optimised for realtime signal processing. Sound and Music Computing, Stockholm, Sweden, 12-17 June 2023. (https://luuma.net/papers/smc2023_Kiefer_RPC.pdf)

and for a more digestible version, here's the poster from the conference:

The project started out a few years ago, with the CoFlo project, using complexity metrics to manage the behaviour of the feedback cello.

Kiefer, C., Overholt, D. and Eldridge, A., 2020. Shaping the behaviour of feedback instruments with complexity-controlled gain dynamics. In 20th International Conference on New Interfaces for Musical Expression (pp. 343-348). (https://vbn.aau.dk/ws/files/395237786/nime2020_paper66.pdf)

Complexity metrics seem to be good at detecting saturated feedback, and then you can use this information to change the gain of the feedback instrument to help it to stay in playable place. The metric, ETC, that we used for the original CoFlo study, has poor realtime performance, so the SMC paper is about a new metric, RPC, which is significantly faster than ETC for realtime signal processing.

There's C++ code available for the RPC algorithm (https://github.com/chriskiefer/libcccrt), and there's also a SuperCollider UGen in this repository.

This week at IIL, i've been trying out the algorithm, with Giacomo Lepri's Chowndolo and the lab's own Proto-Langspil.

This is a short demo of the Langspil - it's set up as a feedback instrument, and CoFlo is catching the emerging feedback and damping the feedback loop. As a result, you hear a cyclic push-pull between the feedback and the compressor.

When we plugged the RPC analyser into the Chowndolo, it showed some potentially interesting reflections of the movement of the instrument.

I spent a while making recordings of the Proto-Langspil, using complexity analysis as part of different feedback systems - more on this soon.

In December, Brain Dead Ensemble played a set in the Xenakis Networked Performance Marathon, part of about 8 hours of live performances, streamed on Youtube. Alice Eldridge and I played from the same space in the UK, while Thor Magnusson played from Iceland. We used Sonobus to share audio; Thor sent individual channels to mix into the feedback loops from the two feedback cellos. The entire mix was sent to Athens and broadcast on their video stream along with our streams from Zoom.

More info on BDE: http://www.emutelab.org/braindeadensemble/

Today I joined 'Embodied Perspectives on Musical AI' workshop for a short presentation, which asked questions about how we should approach the ecosystem of AI/ML tools in instrument design, and what the value might be of approaching these tools in a more embodied way? The video of the presentation should be available through the live stream recording on the conference website. Here are the slides:

The funded period of Feedback Musicianship Network has come to an end, but we're still working hard on some of the outcomes. This week i'm in Copenhagen with Dan Overholt and Gianluca Ella. We're working on a mini-feedback instrument that we will release as open-source hardware. So far, ingredients include homemade exciters, analog circuits from Nicolas Collin's envelope follower and the Serge waveshaper, and the output gain stage from the Crackle Box.