cssAudio - Activefile-genericCSS - ActiveGeneric - ActiveHTML - ActiveJS - ActiveSVG - ActiveText - Activefile-genericVideo - ActiveLovehtmlicon-new-collectionicon-personicon-teamlog-outoctocatpop-outspinnerstartv

Pen Settings

CSS Base

Vendor Prefixing

Add External Stylesheets/Pens

Any URL's added here will be added as <link>s in order, and before the CSS in the editor. If you link to another Pen, it will include the CSS from that Pen. If the preprocessor matches, it will attempt to combine them before processing.

+ add another resource

You're using npm packages, so we've auto-selected Babel for you here, which we require to process imports and make it all work. If you need to use a different JavaScript preprocessor, remove the packages in the npm tab.

Add External Scripts/Pens

Any URL's added here will be added as <script>s in order, and run before the JavaScript in the editor. You can use the URL of any other Pen and it will include the JavaScript from that Pen.

+ add another resource

Use npm Packages

We can make npm packages available for you to use in your JavaScript. We use webpack to prepare them and make them available to import. We'll also process your JavaScript with Babel.

⚠️ This feature can only be used by logged in users.

Code Indentation

     

Save Automatically?

If active, Pens will autosave every 30 seconds after being saved once.

Auto-Updating Preview

If enabled, the preview panel updates automatically as you code. If disabled, use the "Run" button to update.

            
              <article>
  <aside id="aside"></aside>
  <main id="main"></main>
</article>
            
          
!
            
              html, body {
  height: 100%;
}

body {
  background: #ddd;
  color: #222;
}

button {
  padding: 0.5rem 0;
  width: calc(80% - 1rem);
  max-width: 200px;
  transform: translateX(0.5rem);
  border: none;
  text-align: center;
  background: #fb0;
  font-size: 1.2rem;
  color: white;
  display: block;
  margin: 1rem auto;
  border-radius: 4px;
  animation: pulse 200ms ease-in-out infinite alternate;
  border: 4px solid darken(#fb0, 2%);
  box-shadow: 0px 0px 0px 4px rgba(0,0,0,0.1);
  text-transform: uppercase;
  letter-spacing: 0.125em;
  .pause { display: none; }
  &.active {
    animation: none;
    background: #222;
    border-color: #000;
    .pause { display: block; }
    .play { display: none; }
  }
}

@keyframes pulse {
  from { transform: translateX(0.5rem) scale(1); }
  to   { transform: translateX(0.5rem) scale(1.1); }
}

.keyboard {
  position: fixed;
  top: 0;
  margin: 0;
  left: 50%;
  z-index: 2;
  width: calc(100% - 2rem);
  max-width: calc(1400px - 1rem);
  border-bottom: 4px solid #ddd;
  transform: translateX(-50%);

  div {
    background: #fff;
    height: 40px;
    flex: 3;
    margin: 1px;
    &[class*="is"] {
      flex: 2;
      background: #222;
    }
    &.active-b,
    &.active-t {
      background: #FB0;
      &[class*="is"] {
        background: darken(#FB0, 20%);
      }
    }
  }
}


article {
  max-width: 1400px;
  display: flex;
  flex-direction: column;
  padding-top: calc(40px + 3rem);
  padding-bottom: 5rem;
  width: calc(100% - 1rem);
  margin: 0 auto;
}

main, aside {
  width: 100%;
}

aside,
main {
  display: flex;
  justify-content: space-between;
  flex-wrap: wrap;
}

aside {
  section { width: 100%; }
}

@media (min-width: 800px) {
  article {
    flex-direction: row;
  }
  main {
    width: calc(80% - 1rem);
    order: 1;
  }
  aside {
    display: block;
    order: 2;
    width: 20%;
    margin-right: 1rem;
    .output {
      h1, h2 { flex-basis: auto; }
      flex-direction: column;
    }
  }
}

section {
  width: 100%;
  margin: 0.5rem;
  display: flex;
  flex-wrap: wrap;
  box-sizing: border-box;
  background: #f0f0f0;
  padding: 1rem;
  h1, h2 {
    margin-top: 0;
    flex-basis: 100%;
    margin-left: 1px;
    margin-right: 1px;
    line-height: 1;
    text-align: left;
  }
  h1 { font-size: 1.2em; }
  h2 { font-size: 1em; }
  > span {
    flex: 1;
    box-sizing: border-box;
    text-align: center;
    padding: 0.5em;
    margin: 1px;
    border: 1px solid #ccc;
    color: #444;
    font-size: 0.6em;
    text-transform: uppercase;
    letter-spacing: 0.125em;
    padding-top: 0.75em;
    sup { font-size: 0.6em; margin-left: -2px; }
  }
  &:not(.keyboard) {
    margin: 0.5rem;
    border-radius: 4px;
    box-shadow: 0px 2px 0px 2px #d9d9d9;
    
    div {
      box-sizing: border-box;
      cursor: pointer;
      text-align: center;
      padding: 0.5em;
      margin: 1px;
      background: white;
      font-size: 0.6em;
      text-transform: uppercase;
      letter-spacing: 0.125em;
      flex: 1 0 auto;
      
      &:hover {
        background: #ccc;
      }
      &[class$="-current"] {
        background: #FB0;
        pointer-events: none;
      }
    }
  }
  &.chord {
    > div {
      background: transparent;
      padding: 0;
      margin-top: 0; margin-bottom: 0;
      display: flex;
      flex-direction: column;
      font-size: 1em;
      + div { margin-left: 0.5em; }
      &:hover {
        background: transparent;
      }
      &.active {
        box-shadow: 0px 0px 0px 1px #fb0;
      }
      div {
        flex: 1;
        background: white;
        text-transform: none;
      }
    }
  }
  &.keys {
    div {
      flex-basis: calc(16.66% - 2px);
      sup {
        pointer-events: none;
        font-size: 0.6em;
      }
    }
  }
  &.patterns {
    align-content: center;
    div { 
      max-width: 20%; flex-basis: 20%; 
      flex-basis: calc(16.66% - 2px);
    }
    @media (min-width: 800px) {
      div { max-width: 20%; }
      &.patterns-720 > div { flex-basis: calc(10% - 2px); }
      &.patterns-120 > div { flex-basis: calc(12% - 2px); }
      &.patterns-24 > div { flex-basis: calc(12% - 2px); }
      &.patterns-6 > div { flex-basis: calc(10% - 2px); }
    }
  }
  
  @media(min-width: 800px) {
    // grid
    &.chord { 
      flex-basis: calc(100% - 1rem);
    }
    &.keys, &.modes, &.steps, &.type { 
      flex-basis: calc(50% - 1rem);
    }
  }
  
  &.chord > div, &.bpm, &.keys, &.modes, &.steps, &.type { 
    > div {
      display: flex; 
      align-items: center; 
      justify-content: center; 
      text-align: center; 
    }
  }
}

svg {
  width: 100%;
  height: auto;
  pointer-events: none;
  polyline { 
    fill: none; 
    stroke: black;
    stroke-linecap: round;
    stroke-linejoin: round;
  }
}
            
          
!
            
              console.clear();
document.documentElement.addEventListener('mousedown', () => {
  if (Tone.context.state !== 'running') Tone.context.resume();
});
/**
 * MusicalScale
 * generate a scale of music
 * https://codepen.io/jakealbaugh/pen/NrdEYL/
 *
 * @param key {String} 
     the root of the key. flats will be converted to sharps.
       C, C#, D, D#, E, F, F#, G, G#, A, A#, B
 * @param mode {String} 
     desired mode.
       ionian, dorian, phrygian, lydian, mixolydian, aeolian, locrian, 
     can also pass in:
       major, minor, melodic, harmonic
 *
 * @return {Object}
     _scale: scale info
     key: the scale key
     mode: the scale mode id
     notes: an array of notes
       step: index of note in key
       note: the actual note
       rel_octave: 0 || 1, in root octave or next
       triad: major, minor, diminished, or augmented triad for this note
         interval: I, ii, etc
         type: min, maj, dim, aug
         notes: array of notes in the triad
           note: the note
           rel_octave: 0 || 1 || 2, relative to key root octave
 */

class MusicalScale {
  constructor(params) {
    this.dict = this._loadDictionary();
    let errors = this._errors(params);
    if(errors) return;
    this.updateScale = this.pubUpdateScale;

    this._loadScale(params);
  };
  
  pubUpdateScale(params) {
    let errors = this._errors(params);
    if(errors) return;
    this._loadScale(params);
  };
  
  _loadScale(params) {
    // clean up the key param
    this.key = this._paramKey(params.key);
    // set the mode
    this.mode = params.mode;
    this.notes = [];
    this._scale = this.dict.scales[this._paramMode(this.mode)];
    
    // notes to cycle through
    let keys = this.dict.keys;
    // starting index for key loop
    let offset = keys.indexOf(this.key);
    for(let s = 0; s < this._scale.steps.length; s++) {
      let step = this._scale.steps[s];
      let idx = (offset + step) % keys.length;
      // relative octave. 0 = same as root, 1 = next ocave up
      let rel_octave = (offset + step) > keys.length - 1 ? 1 : 0;
      // generate the relative triads
      let triad = this._genTriad(s, idx, rel_octave, this._scale.triads[s]);
      // define the note
      let note = { step: s, note: keys[idx], rel_octave: rel_octave, triad: triad };
      // add the note
      this.notes.push(note);
    }
  };
  
  // create a chord of notes based on chord type
  _genTriad(s, offset, octave, t) {
    // get the steps for this chord type
    let steps = this.dict.triads[t];
    // instantiate the chord
    let chord = { type: t, interval: this._intervalFromType(s, t), notes: [] };
    // load the notes
    let keys = this.dict.keys;
    for(let i = 0; i < steps.length; i++) {
      let step = steps[i];
      let idx = (offset + step) % keys.length;
      // relative octave to base
      let rel_octave = (offset + step) > keys.length - 1 ? octave + 1 : octave;
      // define the note
      chord.notes.push({ note: keys[idx], rel_octave: rel_octave });
    }
    return chord;
  };
  
  // proper interval notation from the step and type
  _intervalFromType(step, type) {
    let steps = 'i ii iii iv v vi vii'.split(' ');
    let s = steps[step];
    switch(type) {
      case 'maj':
        s = s.toUpperCase(); break;
      case 'min':
        s = s; break;
      case 'aug':
        s = s.toUpperCase() + '+'; break;
      case 'dim':
        s = s + '°'; break;
    }
    return s;
  };
  
  _errors(params) {
    if(this.dict.keys.indexOf(params.key) === -1) {
      if(Object.keys(this.dict.flat_sharp).indexOf(params.key) === -1) {
        return console.error(`${params.key} is an invalid key. ${this.dict.keys.join(', ')}`);
      }
    } else if(this.dict.modes.indexOf(params.mode) === -1) {
      return console.error(`${params.mode} is an invalid mode. ${this.dict.modes.join(', ')}`);
    } else {
      return false;
    }
  };
  
  _loadDictionary() {
    return {
      keys: 'C C# D D# E F F# G G# A A# B'.split(' '),
      scales: {
        ion: {
          name: 'Ionian',
          steps: this._genSteps('W W H W W W H'),
          dominance: [3,0,1,0,2,0,1],
          triads: this._genTriads(0)
        },
        dor: {
          name: 'Dorian',
          steps: this._genSteps('W H W W W H W'),
          dominance: [3,0,1,0,2,2,1],
          triads: this._genTriads(1)
        },
        phr: {
          name: 'Phrygian',
          steps: this._genSteps('H W W W H W W'),
          dominance: [3,2,1,0,2,0,1],
          triads: this._genTriads(2)
        },
        lyd: {
          name: 'Lydian',
          steps: this._genSteps('W W W H W W H'),
          dominance: [3,0,1,2,2,0,1],
          triads: this._genTriads(3)
        },
        mix: {
          name: 'Mixolydian',
          steps: this._genSteps('W W H W W H W'),
          dominance: [3,0,1,0,2,0,2],
          triads: this._genTriads(4)
        },
        aeo: {
          name: 'Aeolian',
          steps: this._genSteps('W H W W H W W'),
          dominance: [3,0,1,0,2,0,1],
          triads: this._genTriads(5)
        },
        loc: {
          name: 'Locrian',
          steps: this._genSteps('H W W H W W W'),
          dominance: [3,0,1,0,3,0,0],
          triads: this._genTriads(6)
        },
        mel: {
          name: 'Melodic Minor',
          steps: this._genSteps('W H W W W W H'),
          dominance: [3,0,1,0,3,0,0],
          triads: 'min min aug maj maj dim dim'.split(' ')
        },
        har: {
          name: 'Harmonic Minor',
          steps: this._genSteps('W H W W H WH H'),
          dominance: [3,0,1,0,3,0,0],
          triads: 'min dim aug min maj maj dim'.split(' ')
        }
      },
      modes: [
        'ionian', 'dorian', 'phrygian', 
        'lydian', 'mixolydian', 'aeolian',
        'locrian', 'major', 'minor', 
        'melodic', 'harmonic'
      ],
      flat_sharp: {
        Cb: 'B',
        Db: 'C#',
        Eb: 'D#',
        Fb: 'E',
        Gb: 'F#',
        Ab: 'G#',
        Bb: 'A#'
      },
      triads: {
        maj: [0,4,7],
        min: [0,3,7],
        dim: [0,3,6],
        aug: [0,4,8]
      }
    };
  };
    
  _paramMode(mode) {
    return {
      minor: 'aeo',
      major: 'ion',
      ionian: 'ion',
      dorian: 'dor',
      phrygian: 'phr',
      lydian: 'lyd',
      mixolydian: 'mix',
      aeolian: 'aeo',
      locrian: 'loc',
      melodic: 'mel',
      harmonic: 'har'
    }[mode];
  };
  
  _paramKey(key) {
    if(this.dict.flat_sharp[key]) return this.dict.flat_sharp[key];
    return key;
  };

  _genTriads(offset) {
    // this is ionian, each mode bumps up one offset.
    let base = 'maj min min maj maj min dim'.split(' ');
    let triads = [];
    for(let i = 0; i < base.length; i++) {
      triads.push(base[(i + offset) % base.length]);
    }
    return triads;
  };
  
  _genSteps(steps_str) {
    let arr = steps_str.split(' ');
    let steps = [0];
    let step = 0;
    for(let i = 0; i < arr.length - 1; i++) {
      let inc = 0;
      switch(arr[i]) {
        case 'W':
          inc = 2; break;
        case 'H':
          inc = 1; break;
        case 'WH':
          inc = 3; break;
      }
      step += inc;
      steps.push(step);
    }
    return steps;
  };
};

/**
  ArpeggioPatterns
  https://codepen.io/jakealbaugh/pen/PzpzEO/
  returns arrays of arpeggio patterns for a given length of notes
  @param steps {Integer} number of steps
  @return {Object}
    patterns: {Array} of arpeggiated index patterns
 */

class ArpeggioPatterns {
  constructor(params) {
    this.steps = params.steps;
    this._loadPatterns();
    this.updatePatterns = this.pubUpdatePatterns;
  };
  
  pubUpdatePatterns(params) {
    this.steps = params.steps;
    this._loadPatterns();
  };
  
  _loadPatterns() {
    this.arr = [];
    this.patterns = [];
    for(let i = 0; i < this.steps; i++) { this.arr.push(i); }
    this._used = [];
    this.permutations = this._permute(this.arr);
    this.looped = this._loop();
    this.patterns = {
      straight: this.permutations,
      looped: this.looped
    };
  };
  
  _permute(input, permutations) {
    permutations = permutations || [];
    var i, ch;
    for (i = 0; i < input.length; i++) {
      ch = input.splice(i, 1)[0];
      this._used.push(ch);
      if (input.length === 0) {
        permutations.push(this._used.slice());
      }
      this._permute(input, permutations);
      input.splice(i, 0, ch);
      this._used.pop();
    }
    return permutations;
  };
  
  _loop() {
    let looped = [];
    for(let p = 0; p < this.permutations.length; p++) {
      let perm = this.permutations[p];
      let arr = Array.from(perm);
      for(let x = 1; x < perm.length - 1; x++) {
        arr.push(perm[perm.length - 1 - x]);
      }
      looped.push(arr);
    }
    return looped;
  };
  
};


/**
  ArpPlayer
  the main app
 */

class ArpPlayer {
  constructor(params) {
    this.container = document.querySelector('#main');
    this.aside = document.querySelector('#aside');
    this.chords = [0,2,6,3,4,2,5,1];
    this.ms_key = 'G';
    this.ms_mode = 'locrian';
    this.ap_steps = 6;
    this.ap_pattern_type = 'straight'; // || 'looped'
    this.ap_pattern_id = 0;
    this.player = {
      chord_step: 0,
      octave_base: 4,
      arp_repeat: 2,
      bass_on: false,
      triad_step: 0,
      step: 0,
      playing: false,
      bpm: 135
    };
    this.chord_count = this.chords.length;
    this._setMusicalScale();
    this._setArpeggioPatterns();
    this._drawKeyboard();
    this._drawOutput();
    this._loadChordSelector();
    this._loadBPMSelector();
    this._loadKeySelector();
    this._loadModeSelector();
    this._loadStepsSelector();
    this._loadTypeSelector();
    this._loadPatternSelector();
    this._loadSynths();
    this._loadTransport();
    
    // change tabs, pause player
    document.addEventListener('visibilitychange', () => {
      this.player.playing = true;
      this.playerToggle();
    });
    
    console.log(this.MS);
  };
  
  _loadSynths() {
    this.channel = {
      master: new Tone.Gain(0.7),
      treb: new Tone.Gain(0.7),
      bass: new Tone.Gain(0.8),
    };
    this.fx = {
      distortion: new Tone.Distortion(0.8),
      reverb: new Tone.Freeverb(0.1, 3000),
      delay: new Tone.PingPongDelay('16n', 0.1),
    };
    this.synths = {
      treb: new Tone.PolySynth(1, Tone.SimpleAM),
      bass: new Tone.DuoSynth()
    };
    
    this.synths.bass.vibratoAmount.value = 0.1;
    this.synths.bass.harmonicity.value = 1.5;
    this.synths.bass.voice0.oscillator.type = 'triangle';
    this.synths.bass.voice0.envelope.attack = 0.05;
    this.synths.bass.voice1.oscillator.type = 'triangle';
    this.synths.bass.voice1.envelope.attack = 0.05;
    
    // fx mixes
    this.fx.distortion.wet.value = 0.2;
    this.fx.reverb.wet.value = 0.2;
    this.fx.delay.wet.value = 0.3;
    // gain levels
    this.channel.master.toMaster();
    this.channel.treb.connect(this.channel.master);
    this.channel.bass.connect(this.channel.master);
    // fx chains
    this.synths.treb.chain(this.fx.delay, this.fx.reverb, this.channel.treb);
    this.synths.bass.chain(this.fx.distortion, this.channel.bass);
  };
  
  _loadTransport() {
    this.playerUpdateBPM = (e) => {
      let el = e.target;
      let bpm = el.getAttribute('data-value');
      this.player.bpm = parseInt(bpm);
      Tone.Transport.bpm.value = this.player.bpm;
      this._utilClassToggle(e.target, 'bpm-current');
    };
    
    this.playerToggle = () => {
      if(this.player.playing) {
        Tone.Transport.pause();
        this.channel.master.gain.value = 0;
        this.play_toggle.classList.remove('active');
      } else {
        Tone.Transport.start();
        this.channel.master.gain.value = 1;
        this.play_toggle.classList.add('active');
      }
      this.player.playing = !this.player.playing;
    };
    
    this.play_toggle = document.createElement('button');
    this.play_toggle.innerHTML = `<span class="play">Play</span><span class="pause">Pause</span>`;
    this.aside.appendChild(this.play_toggle);
    this.play_toggle.addEventListener('touchstart', (e) => {
      Tone.startMobile();
    });
    this.play_toggle.addEventListener('click', (e) => {
      this.playerToggle();
    });
    

    Tone.Transport.bpm.value = this.player.bpm;
    Tone.Transport.scheduleRepeat((time) => {
      let curr_chord = this.player.chord_step % this.chord_count;
      
      let prev = document.querySelector('.chord > div.active');
      if(prev) prev.classList.remove('active');
      let curr = document.querySelector(`.chord > div:nth-of-type(${curr_chord + 1})`);
      if(curr) curr.classList.add('active');

      let chord = this.MS.notes[this.chords[curr_chord]];
      
      // finding the current note
      let notes = chord.triad.notes;
      for(let i = 0; i < Math.ceil(this.ap_steps / 3); i++) {
        notes = notes.concat(notes.map((n) => { return { note: n.note, rel_octave: n.rel_octave + (i + 1)}}));
      }
      let note = notes[this.arpeggio[this.player.step % this.arpeggio.length]];

      // setting bass notes
      let bass_o = chord.rel_octave + 2;
      let bass_1 = chord.note + bass_o;
      
      // slappin da bass
      if(!this.player.bass_on) {
        this.player.bass_on = true;
        this.synths.bass.triggerAttack(bass_1, time);
        this._utilActiveNoteClassToggle([bass_1.replace('#', 'is')], 'active-b');
      }
      
      // bump the step
      this.player.step++;
      
      // changing chords
      if(this.player.step % (this.arpeggio.length * this.player.arp_repeat) === 0) {
        this.player.chord_step++;
        this.player.bass_on = false;
        this.synths.bass.triggerRelease(time);
        this.player.triad_step++;
      }
      // arpin'
      let note_ref = `${note.note}${note.rel_octave + this.player.octave_base}`;
      this._utilActiveNoteClassToggle([note_ref.replace('#', 'is')], 'active-t');
      this.synths.treb.triggerAttackRelease(note_ref, '16n', time);
    }, '16n');
  };
  
  _drawKeyboard() {
    let octaves = [2,3,4,5,6,7];
    let keyboard = document.createElement('section');
    keyboard.classList.add('keyboard');
    this.container.appendChild(keyboard);
    octaves.forEach((octave) => {
      this.MS.dict.keys.forEach((key) => {
        let el = document.createElement('div');
        let classname = key.replace('#', 'is') + octave;
        el.classList.add(classname);
        keyboard.appendChild(el);
      });
    });
  };
  
  _drawOutput() {
    this.output = document.createElement('section');
    this.output.classList.add('output');
    this.aside.appendChild(this.output);
    this._updateOutput();
  };
  
  _updateOutput() {
    this.output.innerHTML = '';
    let title = document.createElement('h1');
    title.innerHTML = 'Output';
    this.output.appendChild(title);
    let description = document.createElement('h2');
    description.innerHTML = `${this.MS.key} ${this.MS._scale.name}`;
    this.output.appendChild(description);
    this.chords.forEach((chord) => {
      let note = this.MS.notes[chord];
      let el = document.createElement('span');
      el.innerHTML = `${note.note.replace('#', '<sup>♯</sup>')} <small>${note.triad.type}</small>`;
      this.output.appendChild(el);
    });
  };
    
  _loadBPMSelector() {
    let bpm_container = document.createElement('section');
    bpm_container.classList.add('bpm');
    this.aside.appendChild(bpm_container);
    let title = document.createElement('h1');
    title.innerHTML = 'Beats Per Minute';
    bpm_container.appendChild(title);
    
    [45,60,75,90,105,120,135,150].forEach((bpm) => {
      let el = document.createElement('div');
      el.setAttribute('data-value', bpm);
      if(bpm === this.player.bpm) el.classList.add('bpm-current');
      el.innerHTML = bpm;
      el.addEventListener('click', (e) => { this.playerUpdateBPM(e); });
      bpm_container.appendChild(el);
    });
  };
  
  _loadChordSelector() {
    this.chord_container = document.createElement('section');
    this.chord_container.classList.add('chord');
    this.container.appendChild(this.chord_container);
    let title = document.createElement('h1');
    title.innerHTML = 'Chord Progression';
    this.chord_container.appendChild(title);
    
    this.msUpdateChords = (e) => {
      let el = e.target;
      let chord = el.getAttribute('data-chord');
      let value = el.getAttribute('data-value');
      this.chords[parseInt(chord)] = value;
      this._utilClassToggle(e.target, `chord-${chord}-current`);
      this._updateOutput();
    };
    
    for(let c = 0; c < this.chord_count; c++) {
      let chord_el = document.createElement('div');
      this.MS.notes.forEach((note, i) => {
        let el = document.createElement('div');
        el.setAttribute('data-value', i);
        el.setAttribute('data-chord', c);
        if(i === this.chords[c]) el.classList.add(`chord-${c}-current`);
        el.innerHTML = 'i ii iii iv v vi vii'.split(' ')[i];
        el.addEventListener('click', (e) => { this.msUpdateChords(e); });
        chord_el.appendChild(el);
      });
      this.chord_container.appendChild(chord_el);
    }
    
    this._updateChords();
  };
  
  _updateChords() {
    this.MS.notes.forEach((note, i) => {
      let updates = document.querySelectorAll(`.chord div > div:nth-child(${i + 1})`);
      for(let u = 0; u < updates.length; u++) {
        updates[u].innerHTML = note.triad.interval;
      }
    });
  };
  
  _loadKeySelector() {
    let key_container = document.createElement('section');
    key_container.classList.add('keys');
    this.container.appendChild(key_container);
    let title = document.createElement('h1');
    title.innerHTML = 'Tonic / Root';
    key_container.appendChild(title);
    
    this.MS.dict.keys.forEach((key) => {
      let el = document.createElement('div');
      el.setAttribute('data-value', key);
      if(key === this.ms_key) el.classList.add('key-current');
      el.innerHTML = key;
      el.addEventListener('click', (e) => { this.msUpdateKey(e); });
      key_container.appendChild(el);
    });
  };
  
  _loadModeSelector() {
    let mode_container = document.createElement('section');
    mode_container.classList.add('modes');
    this.container.appendChild(mode_container);
    let title = document.createElement('h1');
    title.innerHTML = 'Mode';
    mode_container.appendChild(title);
    
    this.MS.dict.modes.forEach((mode) => {
      let el = document.createElement('div');
      el.setAttribute('data-value', mode);
      if(mode === this.ms_mode) el.classList.add('mode-current');
      el.innerHTML = mode;
      el.addEventListener('click', (e) => { this.msUpdateMode(e); });
      mode_container.appendChild(el);
    });
  };
  
  _loadTypeSelector() {
    let type_container = document.createElement('section');
    type_container.classList.add('type');
    this.container.appendChild(type_container);
    let title = document.createElement('h1');
    title.innerHTML = 'Arpeggio Type';
    type_container.appendChild(title);
    
    ['straight', 'looped'].forEach((step) => {
      let el = document.createElement('div');
      el.setAttribute('data-value', step);
      if(step === this.ap_pattern_type) el.classList.add('type-current');
      el.innerHTML = step;
      el.addEventListener('click', (e) => { this.apUpdatePatternType(e); });
      type_container.appendChild(el);
    });
  };
  
  _loadStepsSelector() {
    let steps_container = document.createElement('section');
    steps_container.classList.add('steps');
    this.container.appendChild(steps_container);
    let title = document.createElement('h1');
    title.innerHTML = 'Arpeggio Steps';
    steps_container.appendChild(title);
    
    [3,4,5,6].forEach((step) => {
      let el = document.createElement('div');
      el.setAttribute('data-value', step);
      if(step === this.ap_steps) el.classList.add('step-current');
      el.innerHTML = step;
      el.addEventListener('click', (e) => { this.apUpdateSteps(e); });
      steps_container.appendChild(el);
    });
  };
  
  _loadPatternSelector() {
    this.pattern_container = document.createElement('section');
    this.pattern_container.classList.add('patterns');
    this.container.appendChild(this.pattern_container);
    this._updatePatternSelector();
  };
  
  _updatePatternSelector() {
    this.pattern_container.innerHTML = '';
    // reset if the id is over
    this.ap_pattern_id = this.ap_pattern_id > this.AP.patterns[this.ap_pattern_type].length - 1 ? 0 : this.ap_pattern_id;
    this.arpeggio = this.AP.patterns[this.ap_pattern_type][this.ap_pattern_id];
    let title = document.createElement('h1');
    title.innerHTML = 'Arpeggio Style';
    this.pattern_container.appendChild(title);
    let patterns = this.AP.patterns[this.ap_pattern_type];
    [720, 120, 24, 6].forEach((count) => { this.pattern_container.classList.remove(`patterns-${count}`); });
    this.pattern_container.classList.add(`patterns-${patterns.length}`);
    patterns.forEach((pattern, i) => {
      let el = document.createElement('div');
      el.setAttribute('data-value', i);
      if(i === this.ap_pattern_id) el.classList.add('id-current');
      el.innerHTML = pattern.join('');
      el.appendChild(this._genPatternSvg(pattern));
      el.addEventListener('click', (e) => { this.apUpdatePatternId(e); });
      this.pattern_container.appendChild(el);
    });
  };
  
  _genPatternSvg(pattern) {
    let hi = Array.from(pattern).sort()[pattern.length - 1];
    let spacing = 2;
    let svgns = 'http://www.w3.org/2000/svg';
    let svg = document.createElementNS('http://www.w3.org/2000/svg', 'svg');
    let width = pattern.length * spacing + (spacing);
    let height = hi + (spacing * 2);
    svg.setAttribute('height', height);
    svg.setAttribute('width', width);
    svg.setAttribute('viewBox', `0 0 ${width} ${height}`);
    svg.setAttributeNS('http://www.w3.org/2000/xmlns/', 'xmlns:xlink', 'http://www.w3.org/1999/xlink');
    let polyline = document.createElementNS(svgns, 'polyline');
    let points = [];
    let x = spacing;
    for(let i = 0; i < pattern.length; i++) {
      let y = height - pattern[i] - spacing;
      points.push(x + ',' + y);
      x += spacing;
    }
    polyline.setAttribute('points', points.join(' '));
    svg.appendChild(polyline);
    return svg;
  };
  
  _setMusicalScale() {
    this.MS = new MusicalScale({ key: this.ms_key, mode: this.ms_mode });
    this.msUpdateKey = (e) => {
      this._utilClassToggle(e.target, 'key-current');
      this.ms_key = e.target.getAttribute('data-value'); 
      this.msUpdateScale(); 
    };
    this.msUpdateMode = (e) => {
      this._utilClassToggle(e.target, 'mode-current');
      this.ms_mode = e.target.getAttribute('data-value');
      this.msUpdateScale();
      this._updateChords();
    };
    this.msUpdateScale = () => { 
      this.MS.updateScale({ key: this.ms_key, mode: this.ms_mode }); 
      this._updateOutput();
    };
  };
  
  _setArpeggioPatterns() {
    this.AP = new ArpeggioPatterns({ steps: this.ap_steps });
    this.apUpdateSteps = (e) => { 
      this._utilClassToggle(e.target, 'step-current');
      let steps = e.target.getAttribute('data-value'); 
      this.ap_steps = parseInt(steps); 
      this.AP.updatePatterns({ steps: steps }); 
      this.apUpdate(); 
      this._updatePatternSelector();
    };
    this.apUpdatePatternType = (e) => { 
      this._utilClassToggle(e.target, 'type-current');
      this.ap_pattern_type = e.target.getAttribute('data-value'); 
      this.apUpdate(); 
      this._updatePatternSelector();
    };
    this.apUpdatePatternId = (e) => { 
      this._utilClassToggle(e.target, 'id-current');
      this.ap_pattern_id = parseInt(e.target.getAttribute('data-value'));
      this.apUpdate(); 
    };
    this.apUpdate = () => { 
      this.arpeggio = this.AP.patterns[this.ap_pattern_type][this.ap_pattern_id]; 
    };
    this.apUpdate();
  };
  
  _utilClassToggle(el, classname) {
    let curr = document.querySelectorAll('.' + classname);
    for(let i = 0; i < curr.length; i++) curr[i].classList.remove(classname);
    el.classList.add(classname);
  };
  
  /**  
  utilActiveNoteClassToggle
  removes all classnames on existing, then adds to an array of note classes
  @param note_classes {Array} [A3, B4]
  @param classname {String} 'active-treble'
 */
  _utilActiveNoteClassToggle = (note_classes, classname) => {
    let removals = document.querySelectorAll(`.${classname}`);
    for(let r = 0; r < removals.length; r++) removals[r].classList.remove(classname);
    let adds = document.querySelectorAll(note_classes.map((n) => { return `.${n}`; }).join(', '));
    for(let a = 0; a < adds.length; a++) adds[a].classList.add(classname);
  };
}

let app = new ArpPlayer();
            
          
!
999px
🕑 One or more of the npm packages you are using needs to be built. You're the first person to ever need it! We're building it right now and your preview will start updating again when it's ready.
Loading ..................

Console