This latest tune continues the explorations of chaotic system generation modules in VCV Rack and miRack. Here, however, I'm making a thicker texture, one that is more chorale like, and one that has a more continuously shaped sense of phrasing. The central core of this piece is Antonio Tuzzi's "Boh!ngler" module, a kind of sample and hold feeding a shift register feedback circuit. It can produce 16 simultaneous (and related) random control sequences. Quite useful. Michael Hetrick's Random Gates distributes the first 8 voltages to 8 separate oscillators, which are then processed through 8 Lindenberg West Coast wave shapers. Processing of the Boh!ngler outputs was done with a set of Holonic Systems Swiss Cheese Knife modules. This piece was made on the iPad, and I thought it would be fun to try out the Apple Pencil as a means of control. This worked wonderfully well - the tiny knobs in miRack responded quite readily to the pencil, and gave me quite fine control, especially of the frequency of the main driving Low Frequency Oscillator. The oscillators are playing in a 25-tone Just Intonation scale - made by adding up several 7 note Erv Wilson additive sequence scales (made in Wilsonic), then mixing them with the inversion of those same scales (following Harry Partch's notion that any good scale should be symmetrical), making the 25 note scale heard here. It consists of mostly very consonant Just intervals with the occasional close and crunchy relationships. When used over a several octave range, with pitches randomly selected by the
Boh!ngler control sequences, the result seems to be a pleasing mix of consonance and dissonance. This is, once again, a live performance, this time on the iPad Pro, improvising within the limits and parameters of the patch.
In 1991, he published a paper, with PK Das and Z. Zheng called "Chaos in an effective four-neuron neural network," in Physics Letters A. 161: 60-66. DOI: 10.1016/0375-9601(91)90545-J The abstract to the article reads "A four-effective-neutron system was constructed and its dynamics analyzed. Chaotic behavior and strange attractors were observed. Lyapunov spectra are presented for these attractors." Although I didn't have access to the article, using Michael Hetrick's realization of the NonLinear Circuits "Neuron" module, I set up a four-neuron chaotic feedback circuit in VCV Rack. As you'll hear, occasionally the circuit does settle into repeating patterns - these might or might not correspond to the strange attractors mentioned in the abstract. Nonetheless, the four-neuron gadget does generate interesting patterns, both as controls for a canonic just-intonation set of three oscillators, and as a sound source in its own right. I set up a nice set of controllers on the Korg nanoKey, and improvisationally performed the piece you hear here. Many thanks to David Dunn for first alerting me to the existence of the NonLinear circuits modules, and to Michael Hetrick for suggesting additions to the four-neuron feedback patch to make it even more chaotic. This piece is a follow up to my Caudal Variations, which was also dedicated to Bill's memory, although the mathematics in this piece might be closer to that described in Bill's paper than in the previous work.
This is the first of 3 related studies exploring canonical structures and random information generation in VCV Rack. In this piece, the random generation system is provided by the Tiny Tricks Modulation Generator MG8 - this produces a different random Low Frequency Oscillator signal with each new trigger input. A different waveform with a different frequency and amplitude is generated from each output with each new pulse. Four of these are mixed together to make a composite signal which is used as an input to a sample-and-hold generator. So each time the "Flipper" button is manually pressed, a new set of LFOs are generated and mixed to make a composite random signal. Sometimes this mix will have a repeating element, and sometimes not. Surfing that is one of the attractions of this patch. The control signal resulting from this is delayed with the Xatto Time delay unit and transposed for the second two voices, making a 3 voice canon at a chosen interval of transposition. There are also 3 sampler modules, which are playing a loop (unsynchronized) from an earlier version of the patch. This patch was made on the iPad Pro running miRack, the iPad version of VCV Rack.
2. Sabaneiev-Scriabin Study. This piece uses a scale based on Russian musicologist/composer Leonid Sabaneiv's description of Scriabin's mystic chord as a series of members of the harmonic series. If you then apply the other six notes of a 12 note scale to similar harmonics, you get a 12 note scale made of all the odd harmonics up to 27, except 23 and 25. For this purpose I divide the scale into two six note chords - the mystic chord, and the "other six notes chord." These are put onto a Cartesian sequencer (called Grid Sequencer in this realization) which is moved about kind of randomly by a changing driving clock divided by 5, 7 and 27.31, each of which controls a different direction though the sequencer. Again, control voltages are delayed in the NYSTHI Xatto time, producing a 3 voice canon. The oscillators here are the Audible Instruments Resonator, a physical modelling module which produces quite nice percussion timbres. The sounds are then panned in stereo with the VCV Sound Stage module. In live performance, made with a Korg box'o'sliders, I'm trying to get a certain sense of elegant phrasing in the overall progression of the piece. This used VCV Rack on my Lenovo desktop computer.
3. Sabaneiev-Scriabin 2: The Rosella in my Front Yard.
In this piece, again using the Sabaneiev-derived 12 note just intonation scale that uses all the odd harmonics through 27 except 23 and 25, the random generation being explored in the Music Thing Modular Turing Machine. This is a random generator that produces both repeating and random patterns and, most interestingly, patterns that are somewhere between repeating and varying randomly. The output of this is applied to the NYSTHI Squonk sequencer, which controls the choices from a 12-note sequence consisting of first, the Scriabin mystic chord, and then the "other six notes of the scale" chord. An oscillator and gated noise make the main complex which is delayed through the NYSTHI Xatto time delays. These can be faded in and out, making various patterns of canonically delayed lines. Additionally, a much slower division of the rhythmic clock controls a single Audible Instruments Resonator, making a series of slowly moving metallic percussion sounds. The mix of all these voices is placed into a NYSTHI Twisted Mverb module, which allows you to freeze the reverb at any moment. In performance I do this both manually, and with a pulse output from the Turing Machine module. This has the effect of producing clouds of harmonic sounds that sustain, cutting out the original sounds. The switching on and off of the reverb freeze is fairly crude, especially when controlled by the pulse out from the Turing Machine, which gives the piece a nicely "torn" or "ripped" sound, to my ear. Again, the aim in live performance is to try and assemble an elegant succession of melodic and textural states. This was made on the iPad Pro using miRack, the version of VCV Rack for iOS.
I hope you enjoy these three small pieces. It was fun making them!
Caudal is a module from the Vult collection (for VCV Rack and Voltage Modular) of Leonard Laguna Ruiz. It simulates a 4-node pendulum, and it can quite easily generate semi-chaotic random voltages. I was introduced to it a couple of years ago by one of my students, Matthew Paine, and I finally got around to looking at it, and using it, a couple of weeks ago. The module has 3 modes: "Pendula," "Planets," and "Fish Tank." The module here is triggering off physically modeled timbres from Audible Instruments "Resonator" module, which also has three modes of resonation ("Modal," "Sympathetic String," and "Modulated/Inharmonic String"). Through the use of feedback patching, we're able to get a patch that changes radically in sound-type and gesture-type from moment to moment. To sweeten the mix, every 30 seconds I manually change either the Caudal mode, or the Resonator mode, or both. A very pleasant 5 minute walk through a chaotic system results.
This piece is dedicated to the memory of my father-in-law, the late Willam C Schieve, quantum physicist extraordinaire. While looking through a list of his papers (and there are a lot of them), I encountered "Chaos in an effective four-neuron neural network." Although that paper is NOT about the pendulum algorithm that Laguna Ruiz is using, I liked the coincidence between the 4-mode pendulum and the 4-neuron neural network. Bill was very skeptical that the mathematics and physics he studied could be applied to music composition. He was more of an 18th century kinda guy, musically. In fact, he introduced me to the music of Johann David Heinichen, whose music is amazing, whether or not it has anything to do with chaos theory, or applications of scientific ideas to musical composition. Here are two URLs for Heinichen's music, if you want to explore it.
(And for an 18th century composer who DID combine the arts and sciences, here's a symphony by William Herschel, who not only discovered Uranus, in his off hours, but also composed symphonies like this as his day job: https://www.youtube.com/watch?v=jZomM6xGH_M)
Meantime, I hope you enjoy this little five minute VCV Rack ramble.
Three articles in the current issue of Soundbytes Magazine. First up is an interview with the delightful Henry Lowengard, developer of many music apps, including Droneo, SrutiBox, Aumi, PolyHarp and many others. This interview was a lot of fun to do, and I hope you find it a lot of fun to read:
Next is a review of a wonderful sample set from UVI - Ircam Solo Instruments 2. This not only samples classical solo acoustic instruments in great detail, but each player contributes a full selection of extended techniques as well, making it incredibly useful for composers of a more experimental bent:
Sunday, November 1, 2020 at 4:13PM 