Tag Archives: computer music

Teaching Materials For Electronic Music

Computer Music Practice, Teaching, , ,

Here are some electronic music examples you can listen to, play, and analyze for college-level music classes. They are introductory, free, and have specific purposes. Disclaimer: These materials are from my repertoire and projects, not references to DAWs or plugins. 

CML Suite – Arpeggios (2020)

Score: Download a PDF or go to page 9 of Google Slides Score

Description: Use the circle of fifths to play an electronic ensemble piece. The entire class can participate as long as each student has access to Chrome Music Lab. 

Recommended Use: 

  • Introductory exercise for electronic music ensemble classes
  • Interactive material for music theory classes when learning the circle of fifths
  • Audience participation piece for a concert

Dot Zip (2024)

Codes: Download a .zip file containing SuperCollider files

Description: 22 music examples and downloadable code for SuperCollider, a free audio coding app. There are no secret techniques. What you see in the code is what you are hearing.

Recommended Use:

Singaporean Crosswalk (2016)

Codes and Score: use the embedded link in the title

Description: Become a human surround sound system mimicking the nature and traffic signals in Singapore. SuperCollider must be installed on the performer’s computer (minimum of 4 performers), but previous experience in SuperCollider or electronic ensemble is not necessary.

Recommended Use:

  • Introductory repertoire for laptop ensemble: 20+ electronic ensembles have performed it in their concerts
  • Interactive material for music technology classes when learning surround sound and multichannel systems
  • Complementary example when learning about Alvin Lucier and classic electronic music repertoire.

Academic Electronic Musician (2026)

Project Page: Web link to Zotero Group Library. Works better on computers than mobile devices. Click on the Items icon in the subfolder when using mobile devices.

Description: A comprehensive example of an electronic musician’s creative practice. Use the tags and built-in search engines to research topics on composition, performance, and career development.

Recommended Use:

Is this useful and interesting? If so, please support by sharing, listening, and attending concerts.

I am also available for in-person workshops and virtual guest talks. Feel free to contact me via @joowonmusic

Control Click – Brief Analysis

Compositions, Research, , ,

Control Click is a sound installation I made in 2016. It’s also the title of my recent album. This article is a short analysis detailing how I made the piece in terms of composition and technology.

Program

Control Click is a sound installation for a place with multiple computers, such as a computer lab or a game room. Using freeware, a typical computer lab turns into a multichannel audiovisual instrument that plays algorithmically generated parts. It sounds like a dream sequence at an arcade.

Listen to the tracks and watch the video before reading the next sections.

Form

Control Click is an electronic octet in which every player (i.e., the computer) plays a melody on the same type of instrument.  The instrument gets a specific instruction to choose rhythm, melody, and timbre. First, each player randomly chooses a melody pattern. The chosen pattern is repeated until the next cue.

The choice of rhythm is separated from that of melody. At a cue, the computer chooses a group of rhythmic values, randomly shuffles the order of the notes, and then repeats the newly-formed rhythmic pattern 4 or 8 times. 

The sound is generated by combining a choice in melodic pattern and a choice in rhythmic pattern. The computer chooses another combination in the next cue. Below is one possible result of the algorithm described so far.

The cue is manually timed and recorded, like a placement of audio or MIDI data in a DAW. The cue also triggers changes in timbre, note duration, and octave transposition. The audio example below demonstrates the mentioned variations.

Finally, when 8 or more computers play and change instrument parameters in sync, the room with the computers can make sounds heard in the piece. Listen to 00:30-01:30 of the Bandcamp link for an example.

Code

The demo is formatted like the code examples in DotZip: there are three separate parts labeled SynthDef, Functions, and Performance. To read, modify, and evaluate the scd file, copy-paste-evaluate the code below in SuperCollider. You will hear sounds when evaluating the performance section after running the SynthDef and Functions sections.

There are three SynthDefs in the linked scd file named Beep, Beep2, and Beep3. The design scheme is the same for all of them, but each uses different oscillators for timbral change. They are simple instruments with controllable frequency modulation rate and amplitude envelope durations.

//1. SynthDef
(

SynthDef("Beep", {
	arg freq =60, amp=0.5,dur=0.5,rate=4;
	var sound,lfo;

	lfo= LFPulse.ar(rate,0.5,mul:freq);
	sound = Saw.ar(freq+lfo);
	sound = sound*(XLine.ar(1,0.00001,dur,doneAction:2));

	Out.ar (0,sound.dup*amp);
}).load(s);

SynthDef("Beep2", {
	arg freq =60, amp=0.5,dur=0.5,rate=4;
	var sound,lfo;

	lfo= LFPulse.ar(rate,0.5,mul:freq);
	sound=LFTri.ar(freq+lfo);
	sound = sound*(XLine.ar(1,0.00001,dur,doneAction:2));

	Out.ar (0,sound.dup*amp);
}).load(s);

SynthDef("Beep3", {
	arg freq =60, amp=0.5,dur=0.5,rate=4;
	var sound,lfo;

	lfo= LFPulse.ar(rate,0.5,mul:freq);
	sound=Pulse.ar(freq+lfo);
	sound = sound*(XLine.ar(1,0.00001,dur,doneAction:2));

	Out.ar (0,sound.dup*amp);
}).load(s);


); //end of SynthDefs

The performance instruction is expressed using a Routine object in SuperCollider. 

//2. Functions
(
~key=63;
~sixteenth=0.2;
~dur=0.5;
~rate=18;
~octave=12*rrand(-2,2);
~rhythm=[[1,1,1,0.5,0.5,1],[1,1,0.5,0.5,0.5,0.5]].choose;
~motif=[[0,3,0,3,0],[3,7,3,7,12],[0,3,7,10,0,7]].choose;
~tempo=1;
~instru=["Beep","Beep2","Beep3"].choose.asString;

~melody=Routine({
	var rhythm;
	loop{
		//freq =60, amp=0.5,dur=0.5,rate=4;
		rhythm=~rhythm.scramble*~sixteenth;
		[4,8].choose.do{
			(rhythm.size).do{
				arg count;
				Synth(~instru,[\freq,(~key+~motif.wrapAt(count)+~octave).midicps,\amp,0.2,\dur,~dur,\rate,~rate]);
				(rhythm.at(count)*~tempo).wait;
			}//~rhythm.size.do
		}//[4,8].choose;
	}//loop

});
); //end of Functions

Once ~melody Routine runs and starts to make sound in the Performance section, one can vary the pattern and timbre by modifying and/or evaluating ~global variables.

//3.Performance
//Evaluate each line separately

~melody.reset;~melody.play;
~melody.stop;

(
~dur=rrand(0.3,3.4); // note duration in seconds
~rate=rrand(8,18); //vibrato rate in Hz
~octave=12*rrand(-2,2); //octave shift
~rhythm=[[1,1,1,0.5,0.5,1], [1,1,0.5,0.5,0.5,0.5,1]].choose; //choose a rhythm pattern 
~motif=[[0,3,0,3,7], [3,7,3,7,12], [0,3,7,10,0,7]].choose; //choose a note sequence
~tempo=[0.5,1,0.25,1.25].choose; //tempo (higher the number, slower the tempo)
~instru=["Beep","Beep2","Beep3"].choose.asString; //choose an instrument
)

In the actual installation, each computer runs the above more SynthDefs for more variety. Instead of manually changing global variables, SystemClock.sched in SuperCollider creates a cue list of events and changes. The changes are generated by a central computer and sent to networked workstations using OSC.

Uniquely Electronic

I cannot think of a way to create a similar sound world to Control Click without using multiple computers. The recordings linked above are an approximation of the actual experience of the piece. The listeners are invited to walk around the computers that emit sounds and lights, which vary each time slightly due to the use of random numbers. Like many live electronic pieces, Control Click is best experienced live.

To learn more about Control Click, read the piece’s blog here. There are many versions of the piece.  To read more analysis of electroacoustic pieces, browse a keyword in Academic Electronic Musician.

Input And Function – Computer Music Composition Method

Compositions, Research,

In the Tool and Variations post, I explained a composition method for electronic music.

  1. Make an instrument
  2. Make variations using the instrument
  3. Organize the variations in a musical order

This method works only if I make ample variations with distinguishable yet similar traits. The production of such sounds involves structured, methodical repetition. Once I have a surplus of sounds, I use musical experience and training to select and sequence some of them.

I use four ways to produce variations from sound sources. The four are categorized by the quantity of inputs and the number of functions.

  • One input with many functions
  • Many inputs with one function
  • Many inputs with many functions
  • One input with one function

An input in the list above is a sound, an audio file, a sample, or any starting point sound. A function is a tool, a plug-in, a DSP patch, or any technique or idea that changes the input. An input processed by a function produces an output that is different yet similar to the input. The input->function->output relationship is fundamental in music technology. Borrowing terms from mathematics, the relationship is expressed with the symbol f(x), where x is an input, f is a function, and f(x) is an output.

xff(x)
GuitarDistortion pedalDistorted guitar sound
VoiceGranular patchGranularized voice
100+ 200300

The following sections provide a detailed explanation of the different methods for producing variations. Each section has diagrams, example music, and composition tips.

One Input With Many Functions

In this method, I limit the type of incoming sounds to one. I compensate for the lack of variety in the source with many plugins, SuperCollider patches, hardware processors, and other electronic transformations. The resulting outputs are different from the original, but listeners can hear that they are related to the source.

The one-input-many-functions model is often observed in interactive electronic music, if we think of an instrument as the input.

  • x: an instrument 
  • f, g, h: effect processors that make a type of variation
  • f(x): resulting sound
  • g(x): resulting sound from another effect processor g
  • h(x): resulting sound from another effect processor h 
  • i(x), j(x), k(x)…

In Armor+2 (2015) for clarinet and computer, a clarinetist plays on stage while the computer performer controls a SuperCollider patch off stage. All computer sounds except for one are a result of processing the clarinet sounds. The audience can hear that the computer parts are clarinet sounds with electronic timbral extensions – In other words, the computer parts sound like a clarinet, but they are not feasible without the help of electronics.

Many Inputs With One Function

At 0:35-1:00 of  Pierre Schaeffer’s Bilude (1979), recordings of everyday objects alternate with the piano part. They sound musically related to the piano part because the electronics were processed under the same rules – edit the audio in sync with the piano part. We can frame this in the context of the Input and Function.

  • x, y, z: different types of inputs (audio recordings of paper, water, scissors, etc.)
  • f: function (edit according to the rhythm of the piano part)
  • f(x): resulting sound (paper sound in the rhythm of the piano part)
  • f(y): resulting sound (water sound in the rhythm of the piano part)
  • f(z): resulting sound (scissor sound in the rhythm of the piano part)
  • f(a), f(b), f(c)…

Applying a common rule or function adds reasons for seemingly random sounds to coexist in an electronic music composition. A shared function forms a shared identity that audiences can listen to and follow.  

The identity can be a musical rule, like the ones in Bilude’s, or a shared tool.  In Piano Triplets (2020), an EP collaboration with Starkey, all tracks use the same signal processing algorithm.  Starkey provided samples made with piano, Buchla, bouncing ball, and synths. I processed them with the ISJS patch made with SuperCollider.  The results of processing these samples with various presets were distinct enough to make three tracks.

Many inputs With Many Functions

One does not have to choose between one of the two methods mentioned above. In many cases, composers use multiple inputs and multiple functions to generate a vast array of variations.

The maximalist approach could be good if the composer is in control of the available sources. In Bilude, the electronic part at the beginning consists of processed piano sounds, which fall under the One Input With Many Functions category. It is followed by the Many Inputs With One Function section, as explained in the previous section. Then the piece mixes two methods in the more rhythmically freer latter half.

I use many input and function approaches for improvisation. When spontaneity is necessary, it is better to prepare an excess of sounds and tools than to run out of techniques. My electronic improvisation setup cannot play traditional scales or rhythms, so I make it up by bringing in many sound sources and using a SuperCollider patch with 10+ effects. 

One Input With One Function

Is processing one input with one function musically useful, then? Yes, if the input or the function is exceptional, and if finding its value takes time. Many tracks in Fan Art (2023) feature a digital instrument presented within a single compositional idea. The minimalist approach gives the audience time to focus on details and subtle changes. My job as a creator of such music is to design an instrument that is interesting enough and then present its various states efficiently. Below is a list of some tracks in Fan Art in the context of input-function-output.

xff(x)
Karplus string instrumentHarmonic progression of BWV 847847 Twins
Organ-like instrumentHarmonic progression of Claire de LuneEnd Credits
LoopRhythmic modulation of SamulnoriOgum Walk

One Input With One Function can also yield unexpected, delightful sounds with feedback.

If a function f processes an input x, and the result f(x) is then processed again by the same function f, the newly iterated output is a new variation. The early and still excellent example is Alvin Lucier’s I Am Sitting In A Room (1969). The piece clearly states its input, function, and output at the beginning, yet the ending result is awestruck. 

* Search for and read computer music composition methods and related articles by visiting my Zotero site: Academic Electronic Musician.

Solo Electronic Improvisation

Computer Music Practice, Performances, Research, ,

Since 2009, I have been presenting a solo set of live electronic music. Among the many electronic performance techniques, I specialize in creating electronic sounds on stage without pre-recorded samples. I use a combination of digital effect processors coded with SuperCollider to improvise a uniquely electronic soundscape in concerts and recordings. For more than a decade, I have marketed myself as an expert in that specific style. It is represented as a yellow rectangle in the diagram below. 

The categorization is not meaningful to anyone else, but it was a useful research goal for me in the 2010s. I share three representative pieces of my solo electronic improvisation for listening and analysis purposes.

Three Examples 

100 Strange Sounds (2012-2014) is a set of one hundred short video recordings featuring my live electronic music techniques. Each piece pairs a sound-making object with my SuperCollider code that processes its sound. I invite viewers to notice and enjoy the unexpected relationship between what they see and what they hear. For example, the sound of a cabbage becomes something else with a bunch of effect processors in 100 Strange Sounds #77. 

Large Intestine (2013) is a piece I made after 100 Strange Sounds #42. As described in the blog on style analysis, the no-input mixer improvisation enhanced with SuperCollider has been my favorite electronic instrument for more than a decade. Large Intestine, as the title suggests, epitomizes my interest in noise, digital signal processing, and improvisation. I plan to play this work in as many concerts as possible in the future.

Touch (2014) is my kitchen-sink piece that pairs multiple sound objects with multiple effects. It’s a summary of 100 Strange Sounds, in which I bring random objects on stage and improvise the combination and sequence of sounds. The piece opened many doors to career opportunities in the 2010s as an electronic music improviser. The techniques and technologies I learned in performing and refining Touch became a source for future non-improvisational compositions for electronic ensembles. 

Technology

All three pieces mentioned above use a variation of a single SuperCollider patch, available for download at this link. And this linked PDF explains the hardware and software setup to perform the pieces (warning: it is a little outdated). 

When I run the patch, it creates a GUI with multiple buttons that trigger customized effects. I control the number and timing of the effects’ on/off states with a mouse click – No MIDI controllers or control surfaces. A few clicks, probably unnoticed by the audience, are enough because I wanted the listeners to focus on the interaction I have with the non-electronic objects on the stage. 

As for the hardware,  I use a couple of microphones for Touch, one audio interface, and a laptop. This article explains the gear I used over the past 11 years.

Technique

Like other improvisations, the key technique in performing solo live electronic music is listening. I listen for variations that the computer part adds to the acoustic instruments, then respond with another instrument or effects. Because I cannot play a scale or harmony with the instrument (like cabbage), the listen-and-react decisions are often non-musical and raw. “The current sound is long, so I’ll play short sounds next.” “I will go from a simple to a complex texture.”  “The sound is very high in pitch. I’ll complement it with a very low rumble.” I also ask questions and try to come up with the best answer on stage. “What happens if I granularize the chattering teeth sound?” “The plastic block sounds harsh. Can I make it harsher?” “What is common between a slinky and a coin sound?”  

Free improvisation focusing on reactions and questions is fun, but it can quickly lose control of the length and form. So I plan a specific gesture or sound combination for transitions. The Extension and Connection blog linked earlier has such an example in Touch.  

Annecdote

More than fifteen years of experience in improvising with live electronics forms the foundation of my musicianship. I identified myself as a composer after earning a PhD in composition in 2008, but it did not lead to a gig or collaborations when I moved to Philadelphia for my first job as a music technology professor. The dire situation led me to develop a solo set I can prepare and present quickly in any situation. The strategic change, fortunately, worked, giving me ample opportunity to refine my performance and improvisation techniques. 

These days, I am comfortable identifying myself as a composer-performer of electronic music. My sound may not be fresh or cutting-edge at this point, but I think I have a bit more to contribute to the current solo setup. Perhaps the contribution is a documentation and theorization. Perhaps it is just one more new piece!

More electronic music composition/performance/practice articles are found at the Computer Music Practice project.

Scale – Computer Music Composition Method

Compositions, Computer Music Practice, Research, ,

Control and presentation of sound in different scales is a distinguishable feature of computer music. In this context, scale does not refer to a group of notes in different pitches, like a C major scale. It instead refers to proportions, as in big vs. small, long vs. short, and few vs. many. Music technology is capable of rendering a single musical idea in extreme proportions, and the collection of those sounds could become a composition.

I will demonstrate a scale-based electronic music composition process with Control Click, a sound installation composed in 2016. The piece is an 11-minute site-specific work for eight or more computers, creating an arcade-like environment with electronic blips and blinks. The computers are networked to play the same SuperCollider file, functioning as both a performer and a lighting device. The video below is a version of Control Click presented at the 2016 Third Practice Electroacoustic Music Festival.

Sound Design With Proportions

Featuring various scales/proportions in computer music means applying different values to a control parameter. If one can control the pitch of an electronic instrument, experiment with low Hz and high Hz. If the duration of a note in an electronic instrument could be programmed, make very short and very long sounds. The keyword here is extreme. A computer is capable of following laborious or precise instructions that are difficult or impossible for humans to execute. 

In Control Click, each computer algorithmically generates a melodic line based on a chord. I cannot control the exact sequence of pitches, but I could control the chord type, note duration, and tempo. The range of note duration and their playback pace is wider than that of acoustic instruments, thus capable of creating different timbres and moods. The audio example below plays the melodic line in normal, slightly longer, and very short note durations.

By playing the melodic line heard above with very long note duration and decelerating tempo, I could create the sound below. Note that the tremolo of individual notes reveals more as the note duration becomes longer. Longer and stacked notes with different tremolo rates create a sense of a chord with long reverb.

The sound heard above was inspired by the FFT time-stretching technique, which inspired composers to discover hidden sounds too short to be heard and appreciated in an audio file. The technique can also make a long audio phrase so short that one cannot identify the pitch. In other words, time-stretching scales the duration parameters in extreme proportions. But such an idea is applicable beyond FFT. The audio below is how I applied the duration/tempo scale to the percussion sound.

Composition With Proportions

The idea of applying different proportions can also be applied beyond parameter change. In Control Click, the example sounds in the previous section are meant to be played by multiple computers. But as a site-dependent piece with random number generators, each computer emits a distinguishable note sequence at different physical locations. My goal was to create a sonic environment of an arcade from my childhood – chaotic, overwhelming, and delightful. 

Links below point to the moment in the piece that uses previously mentioned scaling examples in an ensemble format. 

  • The normal melodic line with percussion (1:30)
  • Long note duration (2:30-2:50)
  • Short note duration (5:30-6:00)
  • Extreme extension of note duration and tempo (8:50-10:00)

In the third link, Long note duration, the melodic line is detuned by a random amount at synced timings. The effect of one computer doing so is not so noticeable. But when multiple computers are out of tune in a large space, it creates an impact that I cannot recreate in a concert hall.

Notation of Proportions

The concept of controlling a range and scope of musical parameters, rather than instructing specific notes to play, is transferable to human performance. A proper notation to play an electronic instrument within a limited range can be considered as proportional control of choices. Seven Bird Watchers (2019) for drum machine ensemble is an example.

Seven Bird Watchers uses drum machines with customized sync tracks, and the sync track defines the form—the piece is simply seven sections with an increase in tempi and sonic range.  While the composed sync track holds Korg Volca Beats’ tempo together, the human performers change the drum machine’s parameters according to the score. The score depicts the range of parameters performers can improvise.


For example, the early section has limited parameter changes and choices. It lasts about 35 seconds with a moderate increase and decrease in tempo. The performers, as shown in the score above, have a very limited choice of parameter change – the dark area of the Time/Depth/Pitch/Decay knobs, as well as the dark areas in the instrument choice, are the areas in which the performers can move or use knobs and buttons in Volca Beats.

The latter section, in contrast, has a bigger range of tempo changes with an extended duration of 85 seconds. The performers are free to use the entire range of the knobs with almost all available sounds. The proportion of choices and resulting sounds is more varied. For example, the tempo gets so fast that the sixteenth-note run of some percussion instruments loses sense of rhythm. It starts to sound like a bird chirping.

References

For further study, read Curtis Road’s Microsound. I learned the musical application of scale and proportion from this book. Research the scale and proportion in visual art as well. There are ample examples of how different scales make ordinary events extraordinary. Watching a movie on a big screen feels different than watching it on a phone screen. A slow-motion video effect is fun. Similarly, a sound with varying time scales and contrasting parameter values fascinates me.

Computer Music Composition Method has other related entries. Read them if interested