This writing is based on comments that I sent to Keith Potter and Christopher B. Coleman in August-September 2016 as an answer to their research questions on extreme minimalism and phase shifting in my music.

Petri Kuljuntausta

Minimalism, Phase-Shifting and Sound Installations

September 15, 2016



Since 2005 I have composed many sound installations that are based on only one sound frequency. Immediately I can name the following works:
  • Red Lines (2015), sound, laser lights and mirror installation commissioned by Visitazioni Sound Art Festival, Rome Italy
  • Reflected Movements (2015), sound, laser lights and mirror installation, AFS15 / Art Fair Suomi
  • Transporter (2015), sound, laser lights and cellophane sheets, Minimalism Unbounded! conference
  • Resonating Red (2015), sound and laser lights installation, Power Plant Museum, Helsinki
  • Monochromatic Sound Drawings (2015), sound and laser lights installation at Volume sound art symposium, Helsinki
  • Duo & Quartet (2015), sound installation, sound and sand, motorized balls. Rajatila gallery
  • Magnetism (I-II; 2014), sound installation, speakers, magnets, wires, stands, 26 Hz sound frequency, sound players, amplifiers
  • VR Quartet (2014), sound installation, sound and sand
  • AR (2014), sound, sand, video camera installation, AFS14 / Art Fair Suomi
  • Wætergefeall (2013), installation, sound, long plastic sheet
  • A (2013), sound and laser lights installation, sound and water
  • Patterns and Waves (2006), installation, sound, water, laser lights, lights (red room and blue room)
The sound that I usually use in installations is between 24-30Hz. I tune the sound every time when I build the installation, until it creates interesting phenomenas. Most often the frequency is near 26-27Hz. The sound is played at low volume level. Some people might notice it, some don’t. Usually there is two minutes of sound and one-minute of silence, as I don’t like to play sound all the time in the space.
With this low sound frequency I create movement in a matter. With sound I create patterns in sand or water, or this frequency is transformed to laser lights that draw light patterns on the wall. The movement in material starts when the sound starts, and it stops when the sound stops.
In the installation ‘Red Lines’ in Sala Santa Rita, Rome Italy in October 2015, the bass speaker was at the center of the exhibition place. The place was actually a very old catedral at the center of Rome, now it works as a cultural centre. I attached many laser modules on the cone of the speaker. Six big mirrors were in a circle around the speaker that reflected the laser beams to the walls and above the altar. Diameter of the mirror circle was ca. 5-7 meters. Diameter of each mirror was 60 cm. When there was silence, nothing was played through the speaker, and there were only laser beams’ red dots on the walls. But when the low, under 30Hz, sound started to vibrate, the laser lights started to vibrate and they made drawings that were reflected through the mirrors on the walls.
I have used this same ‘one-frequency’ approach in many recent sound installations. When I tune my instrument, the sound installation, the audible sound or the frequency itself is not in the focus actually. Instead I try to find a sound frequency or pitch that creates the most beautiful movement in the matter, or makes the lasers draw interesting figures on the wall.
I wrote the following short text on my installation Red Lines for the Visitazioni sound art festival book. The festival commissioned the installation and it was part of the 2015 festival. The book was released at spring of 2016. This is my original text, in the book this text was translated to Italian.

Red Lines

Sound installation
Six laser modules, audio player, amplifier, bass speaker, six mirrors
A laser is a device that emits light through a process of optical amplification based on the stimulated emission of electromagnetic radiation. A laser differs from other sources of light in that it emits light coherently. Spatial coherence allows a laser to be focused to a tight spot. Spatial coherence also allows a laser beam to stay narrow over great distances (collimation), enabling applications such as laser pointers. Lasers can also have high temporal coherence, which allows them to emit light with a very narrow spectrum, i.e., they can emit a single color of light. Temporal coherence can be used to produce pulses of light as short as a femtosecond. – Wikipedia
In Red Lines installation, a low frequency sound creates resonances that are transmitted to a system of laser lights and mirrors. What emerges from this is a light-painting of the sound. By refraction and multiplication, a redesigned version of the sound spread around the space of Sala Santa Rita where the viewer can concentrate to experience the connection between the sound, light and movement.
I often use frequencies between 24 – 30 Hertz in my sound installations, as low frequencies create the most effective, and visible, movement in different materials, like in sand, film sheet or water.
The sound frequency that I use in Red Lines is 26 Hertz. This frequency is the source for the movement and light drawings. When the speaker doesn’t produce any sound, the laser beams are still and create only tiny red dots around the space. When the sound starts, the dots starts moving and create light paintings on the architectural surfaces of the space.
How the lasers are connected to speaker cone, affects to the drawings. I have tried many different ways to contact the lasers until I found the best solution. Flexible, spring-like, connection boost the vibration mechanically and then the laser drawings are more interesting. But the lasers very seldom create interesting drawings immediately when connected to the speaker cone. They need fine-tuning. If the drawing is lame and uninteresting, I change the direction and angle of the laser module. I turn it and move it, little by little, until the resonance creates a drawing that is interesting. Then I move to the next laser and tune it as well. And so on, until I have fine-tuned all the lasers that are connected to the speaker cone. Each laser light creates its own kind of painting.
I can affect on the look of the drawings, but the figures are not fully under my control. The drawing process is partly accidental and to me this is interesting. My intention is to create the work and start the process, but I don’t have to control all details. I like to communicate with the technology and if the feedback is slightly different than I expected, I try to find the procedures that helps me to get the best results out from the system. When I install the Red Lines next time at a different space, the laser drawings will look totally different.
The central space of Sala Santa Rita has the form of a squashed octagon, with a surface of almost 100 square meters. The physical components of the Red Lines are at the center of the space. At the center is a bass speaker and around the speaker are the 6 circular mirrors (dibond mirrors) in a formation of circle. The diameter of the installation is 600 cm. The diameter of each mirror is 60 cm. The 6 laser modules are connected on the cone of the speaker. The laser beams are headed to the mirrors, and these reflects the beams around the space of Sala Santa Rita. The distance between the drawings and the speaker and mirrors is 10 – 20 meters. The lasers draw the images above the altar, on the walls and roof.
The lasers of the installation are Class 2 lasers (650 nm, 5 mW, 4.5 V). A Class 2 laser is considered to be safe because the blink reflex (glare aversion response to bright lights) will limit the exposure to no more than 0.25 seconds. It only applies to visible-light lasers (400 – 700 nm). Many laser pointers and measuring instruments are Class 2, these lasers are safe but it is not recommended to stare into beam.


I have composed many compositions based on phase shifting technique. Latest work is entitled 1918, a 23-min work, which is based on touching story about the civil war in Finland, told by an old man, who was then, in 1918, a little boy. He told about the soldiers who came to their house and tried to arrest his older brother. They didn’t found him, and as no one helped they put the gun on this boy’s forehead and asked again from his family where is his brother. They didn’t shoot the boy, and left out. But soon they came back and captured all people except this young boy. And the soldiers killed them. The young boy was suddenly orphan, and started to travel and tried to find work. He went to manor and asked a job. The lady of manor said loudly, “Why this hobo is not killed yet!” It was really difficult to listen to this story, it is horrible example on our history, and how neighbours became enemies. The 1918 was released on my CD Emergence. This work could be found from iTunes and other streaming services.
In my book Äänen eXtreme, Engl. eXtreme Sound, from 2006, I wrote several pages about my phase shifting works, but unfortunately the book is in Finnish.
I tend to use rather small fragments of sound and couple the phasing with a looping process, much like Steve Reich did in Come Out and It’s Gonna Rain and few other early work. You can hear that in 1918, and the works on Momentum CD.
The exception is the Momentum composition, where I use rather long sample, which is taken from my string quartet. The sample is the longist that I have ever used in phase shifting, ca. 20 seconds.
I play this loop in three layers, 1. original sample, 2. the sample is transposed 1-oct down, 3. the sample is transposed 1-oct high. Technically the work is based on slow crossfades between these three layers.
Later on I tried to use this simple Transposition/Crossfade/Phase Shifting technique with different kind of sound materials. I believed I could invent a new approach for composition from this basis. I did many tests during the years, but I never succeeded to repeat this process succesfully. This simple idea worked well only in Momentum, with that one source sample. All other tests and works ended to trash can. They didn’t sound good.
The idea of phase shifting is simple, but only seldom you found sound particle that work well and produce interesting phase shifting process. You can’t tell in advance what kind of sample works well. You might have a beautiful and colorful sound, but you have to test it first and listen to what happens during the process and does it work in phase shifting. Usually it doesn’t.


I can manipulate the phase shifting process by re-tuning the soundfiles, or samples. I can affect on how fast, or slow, the phase shifting process happens. I re-tune each sample differently. In past I called this technique as ‘nano tuning’ (of soundfiles / samples). The original soundfile is the starting point. Its first clone is few cents lower, eg. -2 cents. The second clone could be -4 cents lower, third one -6 cents lower, and so on… Usually the last clone is ca. 14 cents below, or lower, from the original sample.
After this pitch modification, transposition, the lenght of each sample is also slightly different. The shortest soundfile is the original, and the soundfile that is tuned most lower, is the longest one. I use this tiny difference — it is question about milliseconds — between the soundfiles as the basis for phase shifting. If I want to create slow phase shifting process, then the soundfiles are tuned closely, only few cents away from each other. If I want faster process, then the distance between the soundfiles is bigger.



In my pieces I usually control the dynamic relation between the phase shifting tracks. This means that I play at some point some phase shifting track/-s few decibels louder, or another track/-s few decibels lower. With this strategy I can eliminate boring moments of straight-ahead process, and bring up to foreground more interesting sound colors or rhythms instead.


I have always used stereofield as one parameter in my phase shifting compositions. The phase shifted soundfiles are distributed to the stereofield in tuning order, from left speaker to right speaker. Usually the original soundfile is on the left corner.
Here is an example.
The full stereofield, from extreme left to extreme right, is:
LEFT +100     CENTER 0      -100 RIGHT
If I use 8 identical soundfiles, the position of each sound in the stereofield is usually close to the following scheme:
+70   +40   +15   +7   -7   -15   -40   -70
When the phase shifting process starts, the process creates ‘waves’ for awhile, and this happen also later every now and then. At start the waves goes from left to right channel. The piece is never static as the relation of the soundfiles changes all the time. At some point, when the process does complicated results, the waves disappear, and then you start to notice sound colors, depending on how the sound subjects meet each other vertically.
The stereophonic phase shifting effect is different if compared to Steve Reich’s technique. Reich composed monoural works, so the spatial dimension is missing from his works.
In stereophonical phase-shifting you might thing that you can even focus on one soundfile as it stays at the same point in the stereofield and only its environment changes — the relation between the phase shifting soundfiles. But your brain doesn’t work this way. You’ll always hear the sum of all, the ear can’t pick up one of the sounds and stay on it.


The ‘Eight Rooms’ is a multichannel installation where I used spatial phase shifting. The speakers are in exhibition space around the visitors, and the phase shifting process happens around the listeners. One of the movements is on the usb stick you got, but that is a stereophonical version. Originally it is a multichannel piece.



In ‘1918’ I developed phase shifting technique further. Usually the phase shifting works are based on one soundfile, but in ‘1918’ I use several samples at the same time. So there are different layers in the piece, each layer has its own ‘sound instrument’, and each layer has its own phase shifting process. These all layers are not 100% full on at all the time, as I control the process by controlling the dynamic curve of each layer.

A COMMENT ON the Violin Tone Orchestra

In the original VTO, I used 8 identical soundfiles, the original and its 7 clones. I did this version with my Ensoniq EPS 16+ sampler/sequencer. Unfortunately the sampler diskette suddenly broked, and I had only one version saved to DAT, digital tape, and that was not full-lenght piece. So, for the Momentum album I realized the piece with a computer software, and in this case I also used the same basic sample. In theory the work should have been the same, but, what was interesting, the piece sounded slightly different in the new technological environment. The 8 samples was now too much, the phase shifting wasn’t clear, it became little bit too muddy. So I decided to use only 6 samples and this sounded good.


Navigator, 2005
Navigator is a noise-based electronic work but it is treated with phase shifting technique. The sound source is a noise sound made by beluga whale. Over the phase shifting process comes and goes whale cries. Jim Nollman from Interspecies Communication commissioned the work from me, together with Green Museum, little later he commissioned a video version of the piece for the EXPO World Fair, Aiichi Japan. I invited Sami van Ingen to make a video for the music and the final ork was screened for the expo visitors, there were millions of them.
“I Wouldn’t Do Nothing But Hurt Myself”, 1998, 9:46
This work is based on speech fragments taken from the Errol Morris’ documentary film The Thin Blue Line, 1988. I sampled different voices (words) from the interviews, and produced phase shifting movement from each voice and connected these movements together simply by making crossfades between the voices.


In 1990s I developed a music style that I called as ‘Wave Music’. This idea followed from my experiences in phase shifting and how the process created waves in a stereophonic field. I have several scores based on repeating motive that slightly change / evolve, and after the motive follows the ‘waves’ of the motive. The motive and its transformations are duplicated in different layers, that follows the motive like in fugue. Eg. in he following example the main motive 1 starts from the first beat, and each identical wave follows one hit later, like this:
1 1 1 1 1 1+ 1+ 1+ 1+ 1+ 2  2  2 …
0 1 1 1 1 1  1+ 1+ 1+ 1+ 1+ 2  2 …
0 0 1 1 1 1  1  1+ 1+ 1+ 1+ 1+ 2 …
0 0 0 1 1 1  1  1  1+ 1+ 1+ 1+ 1+ …
I made the scores with Sibelius software, but I don’t know is it still possible to open the files.
I did Wave Music pieces also for guitar and delay machine. I think some recordings are still on DAT tape.


I have never been interested on harmonic processes or music based on harmonical thinking.
If I use chords, I use harmony as a sound color, or use it as rhythmic element, a percussive sound color. I am more at home with independent lines.