Today’s Groups

pairs

Homework Review

Choose one of your partner’s sketches.

Describe the sketch.
Identify a successful feature of the sketch, explain why you chose it.
Identify a weak feature, explain why you chose it.
Suggest a “polishing move.”

Today’s Learning Objectives

Introduce the p5.js sound library.
Show how to use the oscillator class to generate a tone.
Show how to chain oscillators to create more complex sounds.
Show how to interactively control an oscillator.
Show how to play a pre-recored sound.
Show how to capture sound output.

For Example: Steve Reich

For Example: Yoko Ono

Scream

Assignment

Sketch!

This week explore the p5 sound library.

Begin by completing today’s challenges.
Create some sketches using oscillators and sound file playback.
Look at all of the p5 sound examples to get a sense of what is possible with the library.
Consider digging deeper into the library (.FFT, .Amplitude, .AudioIn would all be good to explore with a sketch)

Challenge: Comp Score

Find a ~30 second video clip, perhaps a commercial or movie scene. Use p5.js to create a sound track to play over the video clip. Consider muting your video or choosing a scene with dialog but no music.

Study Examples and Challenges

Download Example Sketches

Example 1: sketch_oscilator

Change the frame rate to 4 fps.
Change the random call to choose from (-50, 50).
Use an if/else statement to make a 50/50 chance of either adding or subtracting 20 hz from the frequency.
Modify the if/else above to either multiply or divide the frequency by 1.2.
Try changing the oscillator type from sine, to triangle, sawtooth, and square.
Change the (nearly) last line to myOscillator.freq(frequency, .1);. Can you hear the difference?
Instead of choosing frequencies at random, try feeding the position of the mouse into .freq

Example 2: sketch_modulator

Change the carrier frequency to 440; change it back.
Change the modular frequency to 5, then try .1; change it back.
change the modulator amplitude to 10, then try 1000; change it back.
Try changing the shape of the carrier oscillator.
Try changing the shape of the modulator oscillator.

Example 3: sketch_loop

Remove one of the loops.
Make the sound loop over just the words “big trouble”
Make the loop play twice as fast. Tip: rate()
Make it play backwards.
Make it play when the user clicks.

Challenging Challenges

Make a sketch that plays random chords (where chords are any two tones at the same time)
Make a sketch that plays a series of ascending tones, then starts back at a low tone.
Make an instrument: something that accepts user input to control sound.
Add a third oscillator to the modulator example. Have the new oscillator change the frequency of the modulator. Basically chain one modulator into another.

Recording Sound Output

// uses the p5 SoundRecorder and SoundFile classes to record the audio output.
// begins recording when called. records for _length_ time in milliseconds.
function record(length){
    var soundRecorder = new p5.SoundRecorder();
    var soundFile = new p5.SoundFile();
    soundRecorder.record(soundFile);
    setTimeout(function() {
        console.log("Recording Complete");
        soundRecorder.stop();
        save(soundFile, "output.wav");
    }, length);
}