let first = 262;

​

// Array of frequencies in the key

// of C Major.

let frequencies = [

  first,

  first * 9/8,

  first * 5/4,

  first * 4/3,

  first * 3/2,

  first * 5/3,

  first * 15/8,

  first * 2

];

​

// Array of Oscillator objects.

let oscillators = [];

​

let melody; // object for saved song

let tempo = 120;

let noteDuration = 60 / tempo; // Duration of each note in seconds

​

let songs; //array of songs

let songSelect; //variable to keep track of song selected from the dropdown

​

//Step 3a: add preload function here

​

​

function setup() {

  createCanvas(400, 400);

  // Create Oscillator objects.

  for (let freq of frequencies) {

    let osc = new Oscillator(freq);

    osc.amp(0);

    osc.start();

    oscillators.push(osc);

  }

  let button = createButton('Play Song');

  button.position(150, 100);

  button.mousePressed(play);

  // Create a dropdown to select a song.

  songSelect = createSelect();

  songSelect.position(100, 150);

  //Step 3b: draw available song files here

}

​

//Step 3c: write loadSong() function here

​

​

​

function draw() {

  background(220);

}

​

//play all the notes in the melody object

function play() {

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

    let n = melody.notes[i];

    setTimeout(function() { playNote(n); }, noteDuration * 1000 * i);

  }

}

​

//turn on the oscillator to play note

function playNote(n) {

  oscillators[n].amp(1, 0.01); // Start playing the note

  setTimeout(function() { stopNote(n); }, noteDuration * 1000); // Stop after the duration

}

​

//turn off the oscillator to stop note

function stopNote(n) {

  oscillators[n].amp(0); // Stop playing the note

}

​