let osc;

​

//diatonic ratio

ratios = [1, 1.125, 1.25, 1.33, 1.5, 1.66, 1.875, 2];

​

//pentatonic = skip 1.34, 1.875

​

function setup() {

  createCanvas(400, 400);

  osc = new p5.Oscillator();

  osc.setType("sine");

  osc.freq(0);

  osc.start();

}

​

function draw() {

  background(220);

}

​

let BASE = 200;

let t = 0;

​

function keyPressed() {

/*

  let f = random(50,500);   //sci-fi

  let f = random(200,400);  //bizarre

  let f = random(50,200);   //low freq, cave, tunnel

  let r = random(ratios);   //diatonic scale of index value

*/

  //let r = noise(t) * 8      //average of random value

  //t += 1;

​

  //if random is greater than 0.3, use 0.5, if not use 1 - in line conditional

  t += random(1) > 0.3 ? 0.5 : 1;  

  let r = (sin(t) + 1) * 4;    //using sine wave to create a melody

  let f = ratios[floor(r)] * BASE;

​

  osc.freq(f);

}

​