​

const fundamental = 261.63;

let curr = fundamental;

let counter = 1; 

​

function setup() {

  let cnv = createCanvas(200, 200);

  osc = new p5.Oscillator(300);

  background(220);

  text('tap to play', 30, 20);

  text('w => perfect fifth\ns => perfect fifth (down)\nd => octave\na => octave (down)\np => print diff from fundamental', 30, 70);

}

​

function playOscAtFreq(f) {

  osc.start();

  osc.amp(0.5);

​

  osc.freq(f);

  osc.amp(0, 0.7);

}

​

function mousePressed() {

   //fundamental * counter;

  playOscAtFreq(curr);

}

​

function keyPressed() {

  if (key == ' ') {

    reset();

    playOscAtFreq(curr);

  } else if (key == 'a') {

    curr = firstUndertone(curr)

    playOscAtFreq(curr);

  } else if (key == 'd') {

    curr = firstOvertone(curr)

    playOscAtFreq(curr);

  } else if (key == 'w') {

    curr = perfectFifth(curr)

    playOscAtFreq(curr);

  } else if (key == 's') {

    curr = perfectFifthNeg(curr)

    playOscAtFreq(curr);

  } else if (key == 'c') {

    playOscAtFreq(fundamental);

  }

  else if (key == 'p') {

    printDiff(curr);

  }

}

​

function perfectFifth(f) {

  return (f * 3) / 2;

}

​

function reset() {

  curr = fundamental;

}

​

function firstOvertone(f) {

  return f * 2;

}

​

function firstUndertone(f) {

  return f / 2;

}

​

function perfectFifthNeg(f) {

  return (f / 3) * 2;

}

​

function printDiff(f) {

  console.log(fundamental - f);

}