Guy Birkin & Sun Hammer Complexification
Project 1 The Complexification project explores musical complexity through a collaborative process based on a set of rules: 1 Make a short, simple piece of music. 2 Swap copies of the pieces with the other person. 3 Modify the given piece to make it more complex (the given piece must be used, but it can be transformed in any way, and new sounds may be added). 4 IF the result is more complex (as agreed by both participants), GOTO 2, otherwise HALT. In this project, complexity is understood in terms of the quantity and variety of musical elements or patterns. The result is two parallel threads of music, each representing a progression of increasing complexity.
2 01GB A very simple piece of music with just two notes G and B, and a total duration of 23 seconds. Sounds created in REAPER with XILS3 VSTi synth, using ring modulation of sine, square and sawtooth waves and a little reverb. 02SH A freesound.org search for GB2 led to a sample of glass breaking (gb11.aif). This sample was played at MIDI notes G1 and B0, G1 looping the sample at 1567.98ms (1567.98Hz = G) and B0 looping it at 1975.53ms (1975.53 = B). EQs were set to accentuate the same frequencies. Clicks were derived from the G and B tones from 01GB.wav by eliminating as much as possible of the tone s harmonic components. The clicks were then looped at approximately the ratio of frequencies, G:B = ~1:1.25 = 4:5 = 4 bars of G click, 5 bars of B click. The piece is more complex than 01GB because information (frequencies of the original tones) was abstracted from that piece and applied in new ways that added to it. 03GB This piece increases the complexity by increasing the quantity and variety of the elements in the previous piece. This is achieved by using four copies of the file transformed in different ways, and by adding a new sound a melodic line to fit with the bass pattern of the previous piece. From one copy of the file, the bass is isolated. One segment of this is duplicated to make a G-B-G-B-G pattern, with G lasting 4 bars and B lasting 5, as in the previous piece. A second copy contains the higher frequencies alone which is offset half a bar relative to the bass, and includes a delay effect. Both of these tracks are processed with a tremolo effect at different rates and strengths (increasing the complexity by adding variation). Two other copies are processed with a guitar amp modeller and reverb (increasing the complexity by adding harmonic distortion). A simple melodic line is added, composed of a simple synth tone and a symmetrical pattern based on arpeggiated G major and B minor triads.
3 04SH This piece increases complexity through its three components. The first is the MIDI component, which pattern is derived from the MIDI notes of the synth melody from the previous piece. This pattern has been trans formed via inversion based on the G major scale using the low G as the axis. The melody has been flipped, and made to trigger the previous piece from the beginning. The notes in the lower half of this MIDI pattern also trigger the piece playing in reverse from the end. The second component is the hihat pattern, which continues the four bars/five bars idea, but has been reconstructed by cutting and pasting different instances. The complexity has been increased in this sound with the intro duction of some perceived randomness; a gating effect has been added and its threshold automated to duplicate the shape of the MIDI pattern (rescaled to twice its original length). Also, the stereo position and delay feedback follow the same automation. The third component is a product of the previous piece multiplied by itself playing in reverse. This introduces some tonal randomness as well as a component that develops by means other than simple looping. 05GB The aim with this piece was to increase complexity by subtract ing from the previous piece performing operations mainly in the time domain rather than the frequency domain. The original file was processed with granular synthesis into four streams at different rates. Two of these four outputs were further duplicated and processed. Those 6 tracks are combined with a basic percussion (made with a TS808 VSTi) and two tracks based on a field recording of pouring rain, one of which is processed with Fourier synthesis. Added to this composition is some convolution reverb and tape delay effect. Perceived complexity is increased by increasing the number of musical elements and by increasing the variety of those elements, changing their parameters over time. Overall, there is greater variance in tempo and dynamics.
4 06SH This piece increases complexity by rearranging the previous piece in what is perceived as a chaotic fashion. The harmonic element is pushed further toward atonality, while the rhythmic is taken further toward perceived randomness. The previous piece was processed with a Max/MSP patch the function of which is to loop audio within a given time range, which audio is separated into four segments layered into one continuous stream through crossfading. The left channel was set to loop at 1000ms and the right at 999ms, with the right s starting position set at 100ms ahead of the left s in the original file. In addition the rate at which the crossfade layering was applied was faster in the left channel (0.66Hz, as opposed to 0.5Hz in the right). All of this slight variation exists in order to exclude the possibility of both channels playing the same thing. The looping region was programmed to step through the original file at intervals of 1000ms, at a rate starting at once every 1000ms and rising 7ms with each successive pulse. The goal was to begin at a 1000ms/step interval and gradually transition by the end to 2000ms/step (in actuality, the final interval was 2022ms/step). Thus a piece is produced that is approximately halfway between the original piece s length of 2:30, and something twice that length. In order to compound the sound further, the channels were swapped completely and a new recording was made, this time stepping down through the file from the end. The two recordings were played simultaneously, with some simple EQ and volume edits having been made to emphasise certain characteristics. 07GB The aim with this piece was to increase the complexity by transforming the previous piece into a variety of different textures. The process began by cutting the file into short pieces based on trans ient detection. The file was cut into over 4,000 pieces which were then analysed and re-ordered. Two types of analysis were used one based on bit rate and the other on a similar measure that calculated file size divided by length of each piece. Re-ordering the pieces according to the first analysis resulted in an arrangement of pieces from short to long; the other method sorted the pieces from bassy, muffled sound at one end to noisy, trebly sounds at the other. These two methods were used to make two new files each, sorted in opposite directions. The four files provided the basis for the finished piece, and were further processed with distortion, transient modification and EQ. A synth bass was also added to the mix, to provide a tonal centre for the piece that gradually fades in. The resulting piece is more complex because it has a greater variety of sounds, with varying patterns emerging and fading.
5 08SH This piece increases complexity by performing operations on many independent aspects of the previous piece, which are set up to interact with one another in various ways. First, the single loudest and quietest frequencies of 07GB as that piece progresses were extracted as sine waves and mixed using values derived from a jpg image of the spectral anal ysis of the original piece. Each second of the piece (as shown in the image) was analysed for its average strength across all frequencies and that changing value was used to create a dynamic crossfade between the loudest and quietest frequencies. The loudest remained set at an amplitude of 1 while the quietest was reduced to an ampli tude of 0.008 to reflect the piece s title and position in this series of pieces. This was transposed back to the tonal center of G, in which the GB series began. A spectral averaging plugin was used to smear the frequency spectrum and provide a noisy element in cont rast to the very clean sound of loud and quiet sine waves. It was constructed with two copies of the original, one transposed to the tonal center of G, the other to B (and with simple auto mation scaled proportion ately); this echoes the G-B motif from 01GB. The mixed spectral averaging track was linked to the loud and quiet sine waves so that a rise in their volume resulted in a drop in the average s volume. A noise cancellation effect was used in order to extract the noise from the original piece, which was pitched to one octave up. This was then gated at -24dB, which created small bursts of noise (in the begin ning) that gradually become very infrequent and unpredict ably occurring short clicks. At the end of the piece, another sound enters, this one created by convolving the spectrum of the original piece with that of the spectral averaging track. Around the same time, the bass notes from 01GB make a re-appearance, bringing the rather atonal piece back to a recognisable tonal center, and more explicitly reintroducing the G-B motif. 09GB The aim was to produce a piece with few sharp changes, but which constantly evolves throughout. 08SH was processed by smearing the frequencies over time to create a tonal background based on the previous piece, over which was laid four other versions processed with a system of two pairs of filters (developed for the Disquiet Junto) that act on left and right channels separately. These provide rhythmic patterns that vary in stereo placement and frequency bands. The other main element in this piece is the drum track, based on a pattern of MIDI notes generated with an algorithm to produce shifting patterns of beats, sometimes with greater repetition of smaller patterns and sometimes with longer phrases. Also included are a variety of percussive patterns, and am arpeggiated bass line that tries to harmonise with the background elements. Overall, the piece increases complexity by introducing greater variety of patters and textures.
6 10SH The idea behind 10SH was to extend complexity by creating more processes that depend upon and exert influence over one another. This further complex ification, and indeed a more truly interactive relationship amongst its components, is due to several factors. Among these are: more major components, more clearly-defined sections, more random processes, more connected processes across elements, greater thought and process behind individual sounds, and direct sonic relationships between sounds (mostly in the form of sidechained filters, gates and compression). For the drum track, 09GB was divided into sixteen equal parts, each lasting five bars. These are assigned to MIDI notes and triggered with short decay times, one per six- teenth note. Playback is randomised at the outset in such a way as to almost always play the first segment; over time and based on the random function s deviations it expands to incorporate all others in equal ratio to the first. As time progresses these are triggered from progressively further into the sample. Near the end of the first drum section this process reverses. The process is imitated with a much simpler random function later in the song (beginning around 3'30"), playing an octave lower and with significant attack for what sound more like hi-hats. For the granular track, grain, file position and spray parameters are randomised with values 2(n-1) based on velocities coming from the randomised MIDI drum track (using only the exceptions and never the central note, causing more changes as time prog resses). Volume is also connected to the drum algorithm to create a fade-in at the beginning. For the vocals, the Disquiet Junto piece Audiobiography Guy Birkin [disquiet0060-audiobio] was processed twice, once using vocoders and again using convolution reverb, to produce two unique tracks. These are used in different ways throughout; one is tied to the first drum track using gating, another is convolved yet again with part of the granular section, and at the end it functions as input for sidechained compression. The final major component is the sine waves. Two versions were made, each using sixteen sine waves: the first uses letters in the word complexification to extract ratios that are then applied to achieve a general slight pitch increase; the second using sixteen integer partials. The complexification sines track is gated based on an inaudible version of the first drum track, and the 16-partials track is low-pass filtered based on the same track.
7 01SH For this piece, a sample of a bell was quickly found on freesound.org with the ambiguous search term round 1, and taking a look through the top few results. It was important that the locating of the sample should be as fast and easy (and pseudo-random) as possible. This particular sound was chosen for its length (about 40 seconds, approximately the desired length of the piece) and because the resonance of the bell in its decay offered nice possibilities for transformation. The sample was put through a simple Max/ MSP granular patch with 20ms grains, and a few sample recordings were taken, first isolating a low frequency band, next a mid band, and lastly a high band. These were then blended, from one to the next, using simple volume fades to show low, mid and high individually. 02GB The basic idea was to increase the complexity by using two copies of the previous piece. One copy is reversed so that together with the other, which is played forwards, a symmetrical composition is created. The symmetry is broken (and the complexity therefore further increased) by introducing a new element that is asymmetrical a synth bassline that increases in volume over time. 03SH The previous piece was transformed using fragmentation, transposition and phase offset. This was achieved by selecting at random 1000ms segments to be played back over 1500ms in the left channel. For the right channel, the time interval was 30ms longer to cause a slowly accumulating offset. The piece ends after the offset reaches 360º with the final segments in the left and right channels playing in unison. This has not been altered except for a volume fade-in. An additional layer was then added, consisting of the original piece multiplied by itself, and the resulting signal further multiplied by the original. While the first process merely transformed the existing piece, this process of multiplication has extended the complexity of the original.
8 04GB The aim with this piece was to make something heavy to go with the industrial sounds of 03SH. The previous piece was processed quite simply, by pitching it down to the key of D, reversing it and adding tape style delay effect, and with automated EQ rolling off the bass in the middle section. To start with, three lines of distorted electric guitar were used a lead tone and two rhythmic parts. The rhythm parts were later expanded and layered in stereo pairs to create a denser and more complex sound. Two drum tracks provide a percussive accompaniment to the guitars. Complexity is increased by a simple process of adding layer upon layer of extra sounds. To some extent, these additions mask the complexity already present in the previous piece, but this is over-ridden by the harmonic and textural complexity of the additional parts. 05SH The idea behind this piece was to smear the metal of 04GB into a longer, noisy drone. Two simple processes were involved, each of which make this piece more complex than the last. First, a custom device was used which generates six loops at a time the position and length of which are random that overlap as they fade in and out in set durations. Next, the recording made of this looping device was stretched/pitch-shifted up by one and two octaves by two different algorithms, both of which were processed with some light distortion, EQ and delay effects and mixed on top of the original recording. A copy of the original piece was put through a low pass filter at 80Hz and played in full in the second half of the piece, creating the thick bass tone. While the complexity present in the previous piece is smudged and less apparent, the processes involved as well as the micro-rhythms generated by the stretching algorithms and the wider use of the spectrum contribute to the added complexity of the piece.
9 06GB The aim was to switch the focus from a textural drone to rhythmic pattern, adding a range of percussive sounds while retaining elements of the previous piece. This piece has quite a simple construction; 05SH was processed in two ways and a percussion track is added. One copy of 05SH is processed through a Fender Twin Reverb amp emulator with medium gain and some tremolo. A second copy is processed with PaulStretch, without timestretching, with a fairly wide window (48K samples) to smear the sound, and with the output tuned to be mainly tonal rather than noisy. The percussion is generated with an algorithmic sequencer and a TS-808 VSTi. It is composed of two tracks one playing a 16-step sequence which fades in slowly, the other being based on an evolving pattern in which the same sequence is modified by modulating the size of the steps. Complexity is increased by the increase in the variety of sounds (adding percussion and modifying the previous piece) and by introducing a wider range of rhythmic patterns. 07SH The idea of this piece was to carry on with the general character of the previous two Guy Birkin pieces i.e. textural drones complemented by a percussive aspect but to do so in a way that increases complexity. This increase is achieved by elements of randomness and by allowing the components of the piece to interact with one another. In keeping with the syncopated feel of 06GB, a rhythmic track was created, which by means of an arpeggiator alternating between 16th and 32nd notes plays a very brief (approximately 35ms) segment from a randomly-selected starting point from the original file. The playback of the original file also contains randomisation around the frequency modulation of the sample. The melodic component was generated by playing the original through a chain of effects, most notably a series of resonant filters. This was copied twice more, one copy stretched to play an octave higher ( octave+ ) and one an octave lower ( octave- ). The original copy was set up with sidechained compression, so that volume levels from the octave+ copy above the threshold would lower its volume. The octave+ copy was similarly sidechained to the percussive track, and given a sidechained gate, so that levels from the original copy above the threshold would silence the track. The octavecopy was filtered to eliminate frequencies above 110Hz, and sidechained with compression to both the kick drum and the percussive track. The Michael Norris Spectral Tracing plugin was used to transform the incoming signal into sine waves based on the signal s strongest frequencies, which was mixed in lightly over the course of the piece. As a reference to the first piece of this SH series, the bell sample that formed the basis of that piece was used again here, mixed in with portions of the percussive track in similar fashion (randomised playback and frequency modulation). The goal of this is to hint at a spiral-like quality to the increase in complexity over the last six pieces.
10 08GB The idea was to make something more harmonically and texturally complex, using generative composition and found sounds. The starting point of this piece is a version of the previous piece processed to extract the tones by time-smearing (Fourier synthesis with a large sample window). Three MIDI tracks were generated in a similar key to the tonal piece, which play at different tempi (1, 1/2 and 1/6 notes). These fade in and out throughout the piece, and one is doubled and overdriven. A percussion track is added, based on a modified version of one of the synth MIDI tracks, processed with distortion. Background textures come from field recordings (ice in a glass, marine sounds, police helicopter). Other effects used are convolution reverb and simulated tape delay. The variety of natural and synthetic sounds, rhythmic patterns (regular and irregular), and harmonies add to the complexity. Subtle variations of these elements throughout the piece further increase the complexity. 09SH The idea of this piece was to increase complexity by abstracting and expanding on ideas from 08GB and other previous pieces in this series. There are two elements to the track: the drone that forms the backbone of the piece, and the rain recording. The idea of the 1, 1/2 and 1/6 from 08GB was reinterpreted in order to form the sonic backbone of the piece. First, the entirety of that recording was raised several octaves and played as a chord with light delay and distortion effects. This was then pitched down to the length of four minutes, while a copy was pitched down to play twice in four minutes, and another copy to play six times in four minutes. In these, the same tremolo and low pass filters were used; for the first (1) these were automated forward, for the third (1/6), automated backward, and for the second (1/2), automated symmetrically around the centre of the piece. Volume fades were also used symmetrically in the same way. These were all run through a Michael Norris spectral analysis plug-in that accentuates the sine waves of the 1, 2, and 6 strongest frequencies (automated symmetrically). The rain recording was put through the identical series of processes as 01SH (a gradual transition from low to mid to high over 36 seconds), then repitched and stretched to a length more appropriate for this piece. It was also treated lightly with the same 1/2/6 spectral analysis effect applied to the drone, and linked by its amplitude to affect (by lowering, via compression) amplitudes of the corresponding low/mid/high elements of the drone. This piece is more complex than the last due to the mathematical layering of the original piece, the coordination of the automated elements, the elaboration on previous ideas, and the connections between the drone and rain elements.
11 10GB The most difficult one yet. This piece, composed of 18 tracks, uses many of the techniques from earlier pieces. For example, 09SH was processed into three separate tracks using Fourier re-synthesis, distortion, and granular synthesis. A fourth processed version used a new technique a form of dynamics processing that inverts the volume of quiet and loud parts. Through these tracks different elements of 09SH provide the backbone of this piece. Percussion is made of five tracks of separate instruments from an 808-like VSTi (kick, snare, tom, clap and hi-hat) each based on a different generative algorithm, plus a sixth track containing different versions of those parts. Some of the percussion parts change timbre throughout the piece, and many of the patterns repeat and transform, with chaotic (nonrepeating) events also added. Synth1 is used for both the bass part and a bell-like sound. The bass pattern changes somewhat like the drums, while the bell synth goes through a simple sequence, forwards at the start and then backwards at the end, with a different part in the middle. Additional tracks contain a recording of street sounds (traffic, voices, wind) and a part made from processing a recording of Marcel Duchamp s lecture, The Creative Act. Effects include distortion, frequency-shifting, delay, convolution reverb and side-chained compression. At various stages, some tracks were bounced down, processed and mixed back into the composition. Complexity is increased with the same strategy as before increasing both the number and diversity of sounds and rhythms. The aim was to create a piece with many subtly-changing elements that created varying micro-patterns that contributed to a more complex whole.
Tracks 1 10 12
Tracks 11 20 13
Analysis 14