sounide:

sound information agency Ideas, notes, sketches and general by-products of thought during CRiSAP fellowship 2011-2012

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Variables

Variables can store numbers, words, UGens, functions or entire patches

lower case a-z are default, ready declared environment variables

key word ‘var’ allows declaration of bespoke variables

their scope is local to function or block

~variableName allows creation of bespoke environment vars (global)

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SC learning basics

I've been playing with Supercollider without reading the manual. I am just reading the manual now and am recording some revelations for personal use here.

Reading

Read from the middle (inner most function) out - nesting unpacks poetically

Evaluation

Evaluate Maths left to right: 10 + 5 * 4 = 60 !! (not 30)

Equivalence of Functional vs receiver notation:

functional: ("echo", 20) and rand(100)

receiver: ("echo".dup) 100.rand

So message ( arg ) == arg.message

and message ( arg1, arg2 ) == arg1.message( arg2 )

Style dictates when to use which.

UGens generally written as receiver.message (SinOsc.ar())

Receiver notation can string together messages, which can be more readable than high levels of nesting

{1000.0.rand.round(0.01).postln}.dup(100).postln.sort.plot

Enclosures

" Quotation marks " enclose a string of chars to create a string

' single quotes ' create symbols, as does a \backslash

'aSymbol' == \aSymbol (see String and Symbol help for more)

( parentheses ) enclose argument lists and force precedence

[ brackets ] define a collection of items - including Arrays which can mix data types and receive messages

{ braces } define functions

dup(random(1000.0), 3) // picks a number, duplicates it

dup({rand(1000.0)}, 3) // duplicates the rand function

== [ rand(1000.0), rand(1000.0), rand(1000.0) ]

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Live Algorithm Manifesto

The term 'live algorithm' was coined by Tim Blackwell and Michael Young as part of an EPSRC funded network in 2005. The network brought together 70 international researchers to establish an interdisciplinary community of musicians, software engineers and cognitive scientists interest in autonomous musical software. The endeavor marries the practices of free improvisation, live electronics and algorithmic composition.

In their original manifesto, Blackwell and Young suggested that a Live Algorithm should exhibit the following characteristics:

interactivity, autonomy, innovation, idiosyncrasy and comprehensibility

Strong interactivity depends on instigation and surprise as well as response. Individual decision-making is immediate, necessary and basic: when to play or not, when to modify activity in any number of parameters (loudness, pitch, tone quality), when to imitate or ignore another participant, when to ‘agree’ the performance is concluding. When to make a decision. And why.

Without the capacity to innovate, listeners would lose the belief that the LA was truly engaged with the performance instead of merely accompanying it.

The iterative, generative, idiosyncratic world of algorithmic organisation must be accessed, but the mechanical and the predictable must be avoided.

It is the ability to innovate that distinguishes automation from autonomy. It is not hard to generate music of great complexity.

Harder, though, is to ensure that these contributions are comprehensible to fellow performers in real-time who might be hearing these ideas for the first time. (But an incomprehensible, opaque system can be contrasted with a transparent one where the association between input and output is too trivial.)

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Types of Listening

Gaver distinguishes between every daylistening andmusical listening.

Everyday Listening - The Perception of sound-producing events, source: "A single engine propeller plane flying past". Gaver. e.g. Gaver 1993 (Ecological Acoustics)

Musical Listening - The experience of sounds themselves, sensory qualities: "a quasi-harmonic tone lasting approximately 3s with smooth variation in the fundamental frequency and the overall amplitude" Gaver. e.g. Gaver 1993 (Ecological Acoustics)

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he who receives an idea from me, receives instruction himself without lessening mine; as he who lights a taper at mine, receives light without darkening me.

Thomas Jefferson, writing to Isaac McPherson in 1813.

Full text at: http://press-pubs.uchicago.edu/founders/documents/a1_8_8s12.html

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Listening structures. Structures emitting sounds and being structured by the sounds they receive.

in response to Duchamp's note on musical sculpture.

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The self-determined sample player with slidey 'cello pizz. This is the kind of sonic prosthesis I've been after for a while !

I've left the TM beads audio off noise in as I've become rather fond of it.

Next to get it going in a live set up.

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As long as the centuries continue to unfold, the number of books will grow continually, and one can predict that a time will come when it will be almost as difficult to learn anything from books as from the direct study of the whole universe. It will be almost as convenient to search for some bit of truth concealed in nature as it will be to find it hidden away in an immense multitude of bound volumes…

Denis Diderot, Encyclopédie (1755)

French writer and philosopher Denis Diderot published in the Encyclopédie ou dictionnaire des sciences, des arts et des métiers, par une société‚ de gens de lettres an article entitled Encyclopédie. In that he explained that a primary reason for undertaking this enormous writing and publishing project was to manage information overload by providing a rational and comprehensible order to what was already an almost impossibly large and disorganized body of information.

From http://www.historyofinformation.com

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The basic claim of science is objectivity: it attempts, through the application of a well defined methodology, to make statements about the universe. At the very root of this claim, however, lies its weakness: the a priori assumption that objective knowledge constitutes a description of that which his known. Such an assumption begs the question 'What is it to know?' and 'How do we know?'.

—Humberto Maturana, Biology of Cognition, 1970.

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Musical sculpture. Sounds lasting and leaving from different places and forming a sounding sculpture which lasts.

A note in Duchamp's The Green Box (1934). A collection of notes, photographs and sketches made to accompany The Bride Stripped Bare by Her Bachelors, Even. Displayed as a part of the 1968 MOMA show, The Machine as Seen at the End of the Mechanical Age, curated by Pontus Hultén. Reported by Bill Fontana as a turning point for him. (In Bill Fontana, River Sounding.)

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The Machine as heard in the middle of the Information age?

The Machine as Seen at the End of the Mechanical Age was an exhibition of work by over a hundred artists, from 15th to 20th century which illustrated the historical intersections of art and technology.

Hultén, the curator of MOMA in 1968, wrote in the forward:

Technology today is undergoing a critical transition. We are surrounded by the outward manifestation of the mechanical age. Yes, at the same time, the mechanical machine -- which can most easily be defined as an imitation of our muscles -- is losing its dominating position among the tools of mankind; while electronic and chemical devices -- which imitate the processes of the brain and the nervous system -- are becoming increasingly important.

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... the sound arriving at the ear is the analogue of the current state of the physical environment, because as the wave travels, it is charged by each interaction with the environment

Truax, B. Ed. (1984) Acoustic Communication New Jersey: Ablex Publishing. p.15

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Self-determined sound - updates

I've made a few updates on the original algorithm.

First I wanted to create a more coherent relationship between the spectral content of the source sample and the updated playback rate - which determines the temporal structure. In the original,  the rate was updated randomly when an onset was detected.

After trying a few options, I settled for simply setting the new rate in inverse proportion to the strongest partial present at the moment an onset is detected. This creates a simple negative feedback constraint which keeps the playback within sensible limits: when the rate is low, the spectral content will tend to be low, so the new rate is high and vice versa.

In generative terms, what is nice about this is that an indefinite longer term 'harmonic' structure is determined by the short-term fixed spectral content. This provides a literal illustration of the generative metaphors central to musical criticism at the turn of the 19th century: Donald Tovey, for example, wrote of Beethoven's forms as "arising from the inner nature of his materials instead of being imposed from without” ( Tovey, 1935 p.8).

Second I wanted to counterbalance the positive feedback between playback rate and onset detection. Playback rate also of course effects the over all rate of change: not only the absolute time  between potential onsets, but the shape of the  amplitude peaks. These effects are smoothed by setting the probability of changing, given an onset, as a function of current rate (i.e. if it is currently slow, a given onset is more likely to produce a change)

D. F. Tovey, A Companion to Beethonen’s Pianoforte Sonatas. London: Associated Board of the Royal Schools of Music, 1935.

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self-determined sample #2: the sprid

The playback process described previously is used to playing a dripping tap sample.

Applied to a low amplitude, hi(ish) fidelity recording, you begin to get a nice sense of exploration. Even with this slightly crude experiment, you start to really hear the details of the tiny sounds in a new way, not unlike the distorted visual magnifications of a water drop ... 

This makes me think about these types of self-referential processes as meta-active (as opposed to interactive).

To do:

- Work out why clicks occur

- non-linear envelopes for oscbank amplitudes (they end a bit suddenly at the moment)

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Head phone listening advised for this one. Almost an ear cleaner.

Made in: beads.

Sample: Dripping tap (my kitchen sink tap is very old), recorded with a prototype hydrophone from Mr Jez Riley-French.

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self-determined sound #1: the balckbrids

The Italian composer Augusto Di Scipio describes the situation achieved in his Audible Ecosystemic Interface series as one in which:  "Sound sets the conditions of its own existence and development." This series involves a fairly complex set up of adaptive synthesis and analysis modules which in which various generatively-relevant parameters are determined by features of the sound produced according to the acoustic response of the room in which it operates. The concept of self-determined sound is gloriously poetic and beguiling from a computational perspective (more on that later perhaps),  but is it sonically potent ? This exercise imagines and implements a simple sample player which is controlled by features of the sound it creates.

The rules:

Play sample.

Look for onsets

When onset is found:

Resynthesize first 32 partials (with a bank of sine oscillators)

Switch playback direction with probability (p)

Adjust playback rate (currently random, to be developed)

Continue playing ...

Sample: english black birds

Made in: beads.

Some kind fellow has lovingly done a js port of beads so that we may use it with processing.js. But I'm not sure he's ported the analysis tools ... or indeed what would happen if we asked for FFTs in a browser. So in the absence of a live demo, here are some tasters ...

Each extract is using exactly the same settings ... the differences are driven by variation in characteristics of the sound file. An interesting feature if you are interested in Generative Efficiency.

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balckbrid#1