​

let synth1 = new Tone.Synth({

    "volume": -5,

    "oscillator" : {

      "type" : "sine", 

      "phase": 0

    }

});

analyzer1 = new Tone.Waveform(1024);

synth1.connect(analyzer1);

synth1.toMaster();

​

let synth2 = new Tone.Synth({

    "volume": -5,

    "oscillator" : {

      "type" : "sine", 

      "phase": 180

    }

});

analyzer2 = new Tone.Waveform(1024);

synth2.connect(analyzer2);

synth2.toMaster();

​

let ml = new Tone.Loop(melodyLoop, "4n");

let fundamental = 261.6; // middle C

let factors;

//                C      D      E      F      G      A      B        C

// ratios :       1/1,   9/8,   5/4,   4/3,   3/2,   5/3,   15/8,   2/1

// intervals:  unison,   2nd,   3rd,   4th,   5th,   6th,   7th,     octave

​

// ordered by decreasing consonance (perception varies)

// let factors =    [1/1,   2/1,   3/2,   4/3,  5/4,  5/3,  9/8,   15/18];

// which gives us: 

//              unison, octave, fifth, fourth, third, sixth, second, seventh

​

​

function melodyLoop(time) {

  let p = random();

  if(p < 0.9){

    let pos = 0;

    // fundamental

    let note1 = fundamental * factors[pos];

    // a given interval on top

    let note2 = note1 * interval;

​

    synth1.triggerAttackRelease(note1, "4n", time);

    synth2.triggerAttackRelease(note2, "4n", time);

  }

}

​

// Start

function mouseClicked() {

  if (Tone.context.state !== 'running') {

    Tone.context.resume();

  }

​

  Tone.Transport.start();

  ml.start();

}

​

​

let label;

let slider;

​

function setup() {

  createCanvas(400, 400);

  factors = [1/1,   2/1,   3/2,   4/3,   5/4,   5/3,   9/8, 15/8]

  slider = createSlider(0, factors.length - 1, 0, 1);

}

​

function draw() {

  background(0);

  interval = factors[slider.value()];

  let waveform1 = analyzer1.getValue();

  let waveform2 = analyzer2.getValue();

  strokeWeight(2);

  noFill();

  stroke(255);

  beginShape();

  for (let i = 0; i < waveform1.length; i++) {

    let x = map(waveform1[i], -1, 1, 0, width);

    let y = map(waveform2[i], -1, 1, height, 0);

    vertex(x, y);

  }

  endShape();

}