Tag Archives: composition

Computer Music Practice Examples

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Computer Music Practice Examples is a new series featuring the application of computer music technology to instrument design, composition, performance, and presentation. 

Introduction

RMHS: Drone Generator

ISJS: Granular Processor

SIOE: Audio Supercut Generator

APG: Audio Palindrome Generator

Many: Reverb Ambient Generator

Forms to Ponder

CMPE Variety Pack

Youtube Playlist

On Off Fade – Etudes for Electronic Music Ensemble No. 2

Compositions, Research, , ,

Link to Score

An electronic instrument can express a gradual or sudden change of timbre by twisting a knob or a slider. On Off Fade for an electronic ensemble is written to practice deliberately timed change in dynamics, density, and spectrum. The ensemble may consist of a percussion and three or more electronic devices. Specific models of electronic devices or previous experiences in an electronic ensemble are not required to perform this piece.


Instrumentation

Three or more electronic Instruments:

  • A machine that produces noise-like sound is preferred.
  • The performer should be able to control at least the volume and another parameter of the sound continuously. More the controllable parameters, better the instrument.
  • Examples of such devices include a radio, drum machine, no-input mixer, turntable, modular synthesizer, electronic metronome, circuit-bent toys,  and analog television.

One drumset OR drum machine:

  • A drumset consisting of a bass drum and a snare is ideal. Alternatively, one may use a drum machine that can trigger bass drum, snare, and rimshot sounds.
  • A drum machine should also be able to start and stop a preset rhythm.

Performance and Score Instruction
For an ideal balance of sound, adjust the volume of the instruments so that they do not overpower the drumset or the drum machine.
Notation for Electronics:

  • Regular notes and rests: start and stop the sound by increasing and decreasing the volume control. All notes should have a short attack and release time unless notated with crescendo or decrescendo. Respect the duration of the rests.
  • Notes with the + sign: change a parameter. For example, a synthesizer player can turn a filter knob. If there is more than one parameter control, feel free to change multiple parameters.
  • Crescendo and decrescendo: For regular notes, gradually change the volume control (a dynamic marking of n being no sound to ff being the loudest sound possible). For the + notes,  change a parameter.

Notation for Drumset or Drum machine:

  • At the absence of a conductor, the drummer cues the next section.
  • If a snare roll is not possible, trigger a preset rhythm in place of a snare roll.

Hallelujah – for vibraphone and computer

Compositions, Performances, , ,

 

Program Notes

This piece is a praise on things and events that are beyond my comprehension and control. Effect of subtle sonic changes on my mind, body, and soul is an example of such things.

Hardware Setup and Instruments

  1. One vibraphone with a working motor
  2. Soft mallets  and a bow
  3. A computer with SuperCollider : Setup the computer near the vibraphone so that you may see the screen. A Macintosh is preferred but not necessary. The SuperCollider application can be downloaded for free at www.audiosynth.com
  4. Hallelujah.scd file: The file can be downloaded from here
  5. One audio interface and one microphone : Connect a condenser microphone into the input 1 of the interface. Connect the interface to the computer.  Alternatively, you can use a USB microphone and no interface.
  6. A sound reinforcement system: connect the stereo output of the interface to the speaker(s). The speakers should be located in close distance to the vibraphone. Putting the speaker right behind the performer should work in small-medium sized venue.

Performance Notes

  1. Volume : The overall volume of the piece should not be loud. The computer part should be just loud enough to hear the pulsing between the vibraphone and the sine tone parts.
  2. Pedal : Pedal is always on. Muffle notes with the mallet on mm 51 (notated with ‘x’ ).
  3. Motor : Set to slow.  Motor is on from mm 53 to 79.
  4. Bowing : There are three notes in the vibraphone part that needs to be bowed (mm 65, 74, and 76).
  5. Pedal : Setup the vibraphone so that the pedal is always on.
  6. Count-In : Measure 1 starts after four beats of count in. Refer to the Visual Click Track window on the computer screen. The performer may interpret the timing of the notes.
  7. Notation of Computer Part : The computer part has three odd-shaped note heads. The rectangle represents a sine tone that changes its frequency when a vibraphone notes are played. The triangle represents a wobbly tone with rhythmic variation. And the diamond represents a note with rich overtones. All computer parts are long and gradual. You may start to notice the computer part about a measure or two after they are triggered at the notated measures. For example. the rectangular note in measure 5 will start to have a audible volume at around measure 6.

How to Run the Computer Part

  1. Make sure that your audio interface is set as the default input and output device for the computer.
  2. Open Haellelujah.scd file in SuperCollider
  3. Go to Menu and select Language->Evaluate File.
  4. Measure 1 starts after four beats count in.
  5. Press command+period (.) or select Language->Stop to stop the computer part
  6. Repeat steps 2-5 for rehearsal and practice.

 

 

Snake Extension – What I have learned in the Spring semester

Compositions, Research, Teaching, , , , ,

I taught Digital Signal Processing Theory class in the last Spring. I have never studied this hard to teach a course. As a result, I learned (or relearned) about DSP quite a bit. More specifically, I learned to appreciate elegance of “classic” techniques, such as AM, FM, sample-and-hold, and delays. I think I can explain them in digital terms. Most importantly, I learned that digital signal processing is all about (good) math.

The best way to wrap up the semester and summarize what I have learned is to make a piece using the new techniques I have learned.

1. To start the piece, I begin with a sinusoid generated with very slow Low Frequency Oscillator (LFO) on its pitch. The LFO’s shape is made with a  wave shaping function using polynomials. The result is an unusual curve pitch pattern.

2. On this polynomial curve, I add sample and hold. The smooth line gets “steps” in terms of pitch. I change the S&H rate to create different rhythms

3. As the piece progresses, I would like to have some frequency modulation gradually fading in.

4. This should sound fun if I have more of them. Here is an example of all the techniques with four sinusoids. The rate of S&H, the shape of polynomial curve, and the modulation rate of FM are randomly selected for each line.

The resulting sound sounded like a good accompaniment for a noisy electronic piece. So I played a no-input mixer and custom synthesizer over the polynomial pads. I also continued the piece with algorithmically drum part that I have developed for Snake and Ox track in my latest album (more about this track later).

Here’s the final result, Snake Extension. I think I’ll add this to my solo repertoire.