Pen Settings

HTML

CSS

CSS Base

Vendor Prefixing

Add External Stylesheets/Pens

Any URLs added here will be added as <link>s in order, and before the CSS in the editor. You can use the CSS from another Pen by using its URL and the proper URL extension.

+ add another resource

JavaScript

Babel includes JSX processing.

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

Packages

Add Packages

Search for and use JavaScript packages from npm here. By selecting a package, an import statement will be added to the top of the JavaScript editor for this package.

Behavior

Auto Save

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.

Format on Save

If enabled, your code will be formatted when you actively save your Pen. Note: your code becomes un-folded during formatting.

Editor Settings

Code Indentation

Want to change your Syntax Highlighting theme, Fonts and more?

Visit your global Editor Settings.

HTML

              
                <div class="container">
  <div class="controls">
    <div class="left">
      <button id="generate-pattern" class="mdl-button mdl-js-button mdl-button--raised mdl-js-ripple-effect mdl-button--accent">
        Generate New Pattern
      </button>
    </div>
    <label class="control">
      Pattern length
      <input id="pattern-length-control" class="mdl-slider mdl-js-slider" type="range"
    min="1" max="32" value="8" tabindex="0">
    </label>
    <label class="control">
      Pattern Density
      <input id="pattern-density-control" class="mdl-slider mdl-js-slider" type="range"
    min="0" max="1" value="0.5" step="0.1" tabindex="1">
    </label>
  </div>

  <div id="sequencer"></div>
  <div id="loading">
    <div class="mdl-spinner mdl-js-spinner is-active"></div>
  </div>

  <div class="controls">
    <div class="left"></div>
    <label class="control">
      <input id="deviations-control" class="mdl-slider mdl-js-slider" type="range"
    min="0" max="1" value="0.1" step="0.05" tabindex="2">
      Deviations
    </label>
    <label class="control">
      <input id="bpm-control" class="mdl-slider mdl-js-slider" type="range"
    min="10" max="300" value="160" step="1" tabindex="3">
      Tempo
    </label>
  </div>
</div>
              
            
!

CSS

              
                html, body {
  margin: 0;
  padding: 0;
  background-color: #222;
  color: #eee;
}
.container {
  max-width: 80vw;
  height: 80vh;
  margin: 10vh auto 10vh auto;
  display: flex;
  flex-direction: column;
  justify-content: center;
  align-items: stretch;
}
.controls {
  display: flex;
  padding: 20px 5px
}
.controls .left {
  flex: 2;
}
.left button {
  width: 100%;
}
.controls .control {
  flex: 2;
  font-size: 13px;
  text-align: center;
}
.controls .mdl-slider__background-upper {
  background-color: #bbb;
}
#sequencer {
  flex: 1;
  display: none;
}
#loading {
  flex: 1;
  display: flex;
  align-items: center;
  justify-content: center;
}
.sequencer {
  width: 100%;
  display: flex;
  margin: 20px 0;
  perspective: 500px;
  transform-style: preserve-3d;
}
.sequencer .column {
  flex: 1;
  display: flex;
  flex-direction: column;
  transform-style: inherit;
}

.sequencer .cell {
  flex: 1;
  margin: .5px;
  box-sizing: border-box;
  position: relative;
}
.sequencer .cell .full, .sequencer .cell .parts {
  position: absolute;
  left: 0;
  right: 0;
  width: 100%;
  height: 100%;
  z-index: 100;
}
.sequencer .cell .parts {
  display: flex;
}
.sequencer .cell .part {
  flex: 1;
}
              
            
!

JS

              
                // Deep House Drum Samples from soundpacks.com.
// https://soundpacks.com/free-sound-packs/deep-house-drum-samples/
const drumFileNames = {
  clap: [
    'clp_analogue.mp3',
    'clp_applause.mp3',
    'clp_basics.mp3',
    'clp_can.mp3',
    'clp_clap10000.mp3',
    'clp_classic.mp3',
    'clp_clipper.mp3',
    'clp_delma.mp3',
    'clp_donuts.mp3',
    'clp_drastik.mp3',
    'clp_eternity.mp3',
    'clp_happiness.mp3',
    'clp_kiddo.mp3',
    'clp_knowledge.mp3',
    'clp_kournikova.mp3',
    'clp_raw.mp3',
    'clp_scorch.mp3',
    'clp_socute.mp3',
    'clp_sustained.mp3',
    'clp_tayo.mp3',
    'clp_tense.mp3',
    'clp_thinlayer.mp3',
    'clp_verona.mp3'
  ],
  hat: [
    'hat_bestfriend.mp3',
    'hat_omgopen.mp3',
    'hat_bigdeal.mp3',
    'hat_openiner.mp3',
    'hat_blackmamba.mp3',
    'hat_original.mp3',
    'hat_chart.mp3',
    'hat_quentin.mp3',
    'hat_charter.mp3',
    'hat_rawsample.mp3',
    'hat_chipitaka.mp3',
    'hat_retired.mp3',
    'hat_sampleking.mp3',
    'hat_samplekingdom.mp3',
    'hat_closer.mp3',
    'hat_sharp.mp3',
    'hat_collective.mp3',
    'hat_soff.mp3',
    'hat_crackers.mp3',
    'hat_spreadertrick.mp3',
    'hat_critters.mp3',
    'hat_stereosonic.mp3',
    'hat_cuppa.mp3',
    'hat_tameit.mp3',
    'hat_darkstar.mp3',
    'hat_vintagespread.mp3',
    'hat_deephouseopen.mp3',
    'hat_void.mp3',
    'hat_drawn.mp3',
    'hat_freekn.mp3',
    'hat_gater.mp3',
    'hat_glitchbitch.mp3',
    'hat_hatgasm.mp3',
    'hat_hattool.mp3',
    'hat_jelly.mp3',
    'hat_kate.mp3',
    'hat_lights.mp3',
    'hat_lilcloser.mp3',
    'hat_mydustyhouse.mp3',
    'hat_ace.mp3',
    'hat_myfavouriteopen.mp3',
    'hat_addverb.mp3',
    'hat_negative6.mp3',
    'hat_analog.mp3',
    'hat_nice909open.mp3',
    'hat_bebias.mp3',
    'hat_niner0niner.mp3'
  ],
  prc: [
    'prc_home.mp3',
    'prc_itgoespop.mp3',
    'prc_jungledrummer.mp3',
    'prc_knockknock.mp3',
    'prc_reworked.mp3',
    'prc_rolled.mp3',
    'prc_syntheticlav.mp3',
    'prc_trainstation.mp3',
    'prc_u5510n.mp3',
    'prc_vinylshot.mp3',
    'prc_virustiatmos.mp3',
    'prc_youpanit.mp3',
    'prc_808rimmer.mp3',
    'prc_bigdrum.mp3',
    'prc_bongodrm.mp3',
    'prc_bongorock.mp3',
    'prc_boxed.mp3',
    'prc_change.mp3',
    'prc_clav.mp3',
    'prc_congaz.mp3',
    'prc_dnthavacowman.mp3',
    'prc_drop.mp3',
    'prc_emtythepot.mp3',
    'prc_flickingabucket.mp3',
    'prc_foryoursampler.mp3',
    'prc_harmony.mp3',
    'prc_hit.mp3'
  ],
  shaker_tam: [
    'tam_christmassy.mp3',
    'tam_extras.mp3',
    'tam_hohoho.mp3',
    'tam_lifein2d.mp3',
    'tam_mrhat.mp3',
    'shaker_bot.mp3',
    'shaker_broom.mp3',
    'shaker_command.mp3',
    'shaker_halfshake.mp3',
    'shaker_pause.mp3',
    'shaker_quicky.mp3',
    'shaker_really.mp3'
  ],
  snare: [
    'snr_mpc.mp3',
    'snr_myclassicsnare.mp3',
    'snr_owned.mp3',
    'snr_royalty.mp3',
    'snr_rusnarious.mp3',
    'snr_truevintage.mp3',
    'snr_analogging.mp3',
    'snr_answer8bit.mp3',
    'snr_bland.mp3',
    'snr_drm909kit.mp3',
    'snr_dwreal.mp3',
    'snr_housey.mp3'
  ],
  tom: [
    'tom_909fatty.mp3',
    'tom_909onvinyl.mp3',
    'tom_cleansweep.mp3',
    'tom_dept.mp3',
    'tom_discodisco.mp3',
    'tom_eclipse.mp3',
    'tom_enriched.mp3',
    'tom_enrico.mp3',
    'tom_greatwhite.mp3',
    'tom_iloveroland.mp3',
    'tom_madisonave.mp3',
    'tom_ofalltoms.mp3',
    'tom_summerdayze.mp3',
    'tom_taste.mp3',
    'tom_vsneve.mp3'
  ],
  bd_kick: [
    'bd_909dwsd.mp3',
    'bd_chicago.mp3',
    'bd_dandans.mp3',
    'bd_deephouser.mp3',
    'bd_diesel.mp3',
    'bd_dropped.mp3',
    'bd_flir.mp3',
    'bd_gas.mp3',
    'bd_ghost.mp3',
    'bd_hybrid.mp3',
    'bd_isampleoldskool.mp3',
    'bd_liked.mp3',
    'bd_mainroom.mp3',
    'bd_mirror.mp3',
    'bd_nash.mp3',
    'bd_newyear.mp3',
    'bd_organicisin.mp3',
    'bd_outdoor.mp3',
    'bd_shoein.mp3',
    'bd_sodeep.mp3',
    'bd_sonikboom.mp3',
    'bd_streek.mp3',
    'bd_stripped.mp3',
    'bd_sub808.mp3',
    'bd_tech.mp3',
    'bd_tripper.mp3',
    'bd_uma.mp3',
    'bd_untitled.mp3',
    'bd_vintager.mp3',
    'bd_vinylinstereo.mp3'
  ]
};

const drumBuffers = _.transform(
  drumFileNames,
  (res, names, group) =>
    (res[group] = names.map(f => new Tone.Buffer(`https://s3-us-west-2.amazonaws.com/s.cdpn.io/969699/${f}`))),
  {}
);

class Cell {
  constructor() {
    this.full = redom.el('div.full');
    this.parts = [
      redom.el('div.part'),
      redom.el('div.part'),
      redom.el('div.part')
    ];
    this.el = redom.el('div.cell', [
      this.full,
      redom.el('div.parts', this.parts)
    ]);
    this.model = { active: false, probability: 0 };
    this.playing = false;
    this.el.addEventListener('click', () => {
      this.model.active = !this.model.active;
      this.model.probability = 1 - this.model.probability;
      this.update(this.model);
    });
  }

  update(model) {
    const baseColor = `hsl(0, 0%, ${20 + model.probability * 70}%)`;
    redom.setAttr(this.el, {
      style: {
        backgroundColor: baseColor,
        zIndex:
          model.playing !== this.model.playing
            ? triggerCounter++ % 1000
            : this.el.style.zIndex
      }
    });
    this.triggerAnimation(model.playing, baseColor);
    this.model = model;
    this.playing = model.playing;
  }

  triggerAnimation(playing, baseColor) {
    if (playing === 'all' && this.playing !== 'all') {
      this.animateTrigger(this.el, '#EC407A', baseColor);
    }
    this.parts.forEach((part, idx) => {
      const triggerAnimation = playing === idx && this.playing !== idx;
      if (triggerAnimation) this.animateTrigger(part, '#EC407A', 'inherit');
    });
  }

  animateTrigger(el, fromColor, toColor) {
    el.animate(
      [
        {
          backgroundColor: fromColor,
          transform: 'translateZ(30px)'
        },
        { backgroundColor: toColor, transform: 'translateZ(0)' }
      ],
      {
        duration: 750,
        easing: 'cubic-bezier(0.215, 0.61, 0.355, 1)'
      }
    );
  }
}

class Column {
  constructor() {
    this.el = redom.el('div.column');
    this.list = redom.list(this.el, Cell);
  }
  update({ drums, isCurrentStep }) {
    this.list.update(drums);
  }
}

const generateButton = document.querySelector('#generate-pattern');
const patternLengthControl = document.querySelector('#pattern-length-control');
const densityControl = document.querySelector('#pattern-density-control');
const deviationsControl = document.querySelector('#deviations-control');
const bpmControl = document.querySelector('#bpm-control');
const players = [];
const sequencerComponent = redom.list('div.sequencer.mdl-shadow--6dp', Column);

let deviations = 0.1;
let patternLength = 8;
let drumCount = 4;
let density = 0.5;
let bpm = 160;
let drumPattern = generatePattern(
  patternLength,
  drumCount,
  density,
  deviations
);
let triggerCounter = 0;

function getStepGain(step, patternLength) {
  if (step === 0) {
    return 1;
  } else if (step === Math.round(patternLength / 2)) {
    return 0.7;
  } else {
    return 0.3;
  }
}

function generatePattern(patternLength, drumCount, density, deviations) {
  const activeDrums = [
    _.sample(drumBuffers.bd_kick),
    _.sample(drumBuffers.hat),
    _.sample([_.sample(drumBuffers.prc), _.sample(drumBuffers.tom)]),
    _.sample([
      _.sample(drumBuffers.snare),
      _.sample(drumBuffers.clap),
      _.sample(drumBuffers.shaker_tam)
    ])
  ];
  return _.range(patternLength).map(step => ({
    step,
    time: '8n * ' + step,
    drums: activeDrums.map(drum => {
      const gain = getStepGain(step, patternLength);
      const active = Math.random() < density;
      const probability = active ? 1 - deviations / 2 : deviations / 2;
      return {
        drum,
        gain,
        active,
        probability
      };
    })
  }));
}

function renderSequencer(drumPattern) {
  sequencerComponent.update(drumPattern);
}

function playPart(time, { drums, step }) {
  const renderings = new Map();
  drums.forEach(drum => {
    const probability = drum.active ? 1 - deviations / 2 : deviations / 2;
    if (Math.random() < probability) {
      const delayProbability = deviations / 3;
      const tripletProbability = deviations / 10;
      const isDelayed = Math.random() < delayProbability;
      const isTriplet = !isDelayed && Math.random() < tripletProbability;
      const triggers = isTriplet
        ? [
            { time: time, render: 0 },
            { time: time + '+16t', render: 1 },
            { time: time + '+16t+16t', render: 2 }
          ]
        : [{ time: isDelayed ? time + '+16n' : time, render: 'all' }];
      for (const { time, render } of triggers) {
        const player = new Tone.Player(drum.drum)
          .connect(new Tone.Gain(drum.gain).toMaster())
          .start(time);
        players.push(player);
        if (!renderings.has(time)) renderings.set(time, []);
        renderings.get(time).push({ drum, render });
      }
    }
  });
  Tone.Draw.schedule(() => {
    drumPattern.forEach(pt => {
      pt.drums.forEach(d => (d.playing = null));
    });
    renderSequencer(drumPattern);
  }, time);
  for (const [renderTime, drumRenderings] of renderings.entries()) {
    Tone.Draw.schedule(() => {
      drumRenderings.forEach(({ drum, render }) => {
        drum.playing = render;
      });
      renderSequencer(drumPattern);
    }, renderTime);
  }
}

Tone.Transport.bpm.value = bpm;
Tone.Transport.timeSignature = patternLength / 2;
renderSequencer(drumPattern);

const part = new Tone.Part(playPart, drumPattern).start();
part.loop = true;

function regenerate() {
  drumPattern = generatePattern(patternLength, drumCount, density, deviations);
  drumPattern.forEach(pt => {
    part.at(pt.time, pt);
  });
  renderSequencer(drumPattern);
}

generateButton.addEventListener('click', regenerate);
patternLengthControl.addEventListener('input', evt => {
  const length = +evt.target.value;
  if (patternLength !== length) {
    patternLength = length;
    Tone.Transport.timeSignature = patternLength / 2;

    const oldTimes = drumPattern.map(p => p.time);
    regenerate();
    const newTimes = drumPattern.map(p => p.time);
    _.difference(oldTimes, newTimes).forEach(t => part.remove(t));

    part.loopEnd = '1m'; // Make the loop recalculate times after sig change
  }
});
densityControl.addEventListener('input', evt => {
  density = +evt.target.value;
  regenerate();
});
deviationsControl.addEventListener('input', evt => {
  deviations = +evt.target.value;
  drumPattern.forEach(part => {
    part.drums.forEach(drum => {
      drum.probability = drum.active ? 1 - deviations / 2 : deviations / 2;
    });
  });
  renderSequencer(drumPattern);
});
bpmControl.addEventListener('input', evt => {
  Tone.Transport.bpm.value = +evt.target.value;
});

redom.mount(document.querySelector('#sequencer'), sequencerComponent);

Tone.Buffer.on('load', () => {
  document.querySelector('#loading').remove();
  document.querySelector('#sequencer').style.display = 'flex';
  Tone.Transport.start();
  setInterval(() => {
    while (players.length && players[0].state === 'stopped') {
      players.shift().dispose();
    }
  }, 5000);
});

StartAudioContext(Tone.context, generateButton);

              
            
!
999px

Console