let osc;

​

// Middle C frequency.

let myFreq = 262;

​

function setup() {

  createCanvas(400,400);

​

  // Create the Oscillator object.

  osc = new Oscillator(myFreq);

}

​

function draw() {

  background(220);

}

​

function mousePressed() {

  // Toggle the note that is playing 

  if(osc.started){

    osc.stop();

  } else {

    osc.start();

  }

}