CodePen Embed - JavaScript Piano

<body>
  <section id="wrap">
    <header>
      <h1>JS Piano</h1>
      <h2>Use your keyboard. Hover for hints.</h2>
    </header>
    <section id="main">
      <div class="nowplaying"></div>
      <div class="keys">
        <div data-key="65" class="key" data-note="C">
            <span class="hints">A</span>
        </div>
        <div data-key="87" class="key sharp" data-note="C#">
            <span class="hints">W</span>
        </div>
        <div data-key="83" class="key" data-note="D">
            <span class="hints">S</span>
        </div>
        <div data-key="69" class="key sharp" data-note="D#">
            <span class="hints">E</span>
        </div>
        <div data-key="68" class="key" data-note="E">
            <span class="hints">D</span>
        </div>
        <div data-key="70" class="key" data-note="F">
            <span class="hints">F</span>
        </div>
        <div data-key="84" class="key sharp" data-note="F#">
            <span class="hints">T</span>
        </div>
        <div data-key="71" class="key" data-note="G">
            <span class="hints">G</span>
        </div>
        <div data-key="89" class="key sharp" data-note="G#">
            <span class="hints">Y</span>
        </div>
        <div data-key="72" class="key" data-note="A">
            <span class="hints">H</span>
        </div>
        <div data-key="85" class="key sharp" data-note="A#">
            <span class="hints">U</span>
        </div>
        <div data-key="74" class="key" data-note="B">
            <span class="hints">J</span>
        </div>
        <div data-key="75" class="key" data-note="C">
            <span class="hints">K</span>
        </div>
        <div data-key="79" class="key sharp" data-note="C#">
            <span class="hints">O</span>
        </div>
        <div data-key="76" class="key" data-note="D">
            <span class="hints">L</span>
        </div>
        <div data-key="80" class="key sharp" data-note="D#">
            <span class="hints">P</span>
        </div>
        <div data-key="186" class="key" data-note="E">
            <span class="hints">;</span>
        </div>
      </div>

      <audio data-key="65" src="http://carolinegabriel.com/demo/js-keyboard/sounds/040.wav"></audio>
      <audio data-key="87" src="http://carolinegabriel.com/demo/js-keyboard/sounds/041.wav"></audio>
      <audio data-key="83" src="http://carolinegabriel.com/demo/js-keyboard/sounds/042.wav"></audio>
      <audio data-key="69" src="http://carolinegabriel.com/demo/js-keyboard/sounds/043.wav"></audio>
      <audio data-key="68" src="http://carolinegabriel.com/demo/js-keyboard/sounds/044.wav"></audio>
      <audio data-key="70" src="http://carolinegabriel.com/demo/js-keyboard/sounds/045.wav"></audio>
      <audio data-key="84" src="http://carolinegabriel.com/demo/js-keyboard/sounds/046.wav"></audio>
      <audio data-key="71" src="http://carolinegabriel.com/demo/js-keyboard/sounds/047.wav"></audio>
      <audio data-key="89" src="http://carolinegabriel.com/demo/js-keyboard/sounds/048.wav"></audio>
      <audio data-key="72" src="http://carolinegabriel.com/demo/js-keyboard/sounds/049.wav"></audio>
      <audio data-key="85" src="http://carolinegabriel.com/demo/js-keyboard/sounds/050.wav"></audio>
      <audio data-key="74" src="http://carolinegabriel.com/demo/js-keyboard/sounds/051.wav"></audio>
      <audio data-key="75" src="http://carolinegabriel.com/demo/js-keyboard/sounds/052.wav"></audio>
      <audio data-key="79" src="http://carolinegabriel.com/demo/js-keyboard/sounds/053.wav"></audio>
      <audio data-key="76" src="http://carolinegabriel.com/demo/js-keyboard/sounds/054.wav"></audio>
      <audio data-key="80" src="http://carolinegabriel.com/demo/js-keyboard/sounds/055.wav"></audio>
      <audio data-key="186" src="http://carolinegabriel.com/demo/js-keyboard/sounds/056.wav"></audio>
      </section>
  </section>
  <video playsinline autoplay muted loop id="bgvid" poster="http://carolinegabriel.com/demo/js-keyboard/video/bg.jpg">
      <source src="http://carolinegabriel.com/demo/js-keyboard/video/bg.mp4" type="video/mp4">
  </video>
  </body>

html  {
        background: #000;
        font-family: 'Noto Serif', serif;
        -webkit-font-smoothing: antialiased;
        text-align: center;
      }

      video#bgvid { 
        position: fixed;
        top: 50%;
        left: 50%;
        min-width: 100%;
        min-height: 100%;
        width: auto;
        height: auto;
        z-index: -100;
        transform: translateX(-50%) translateY(-50%);
        background-size: cover; 
    }

    header {
      position: relative;
      margin: 30px 0;
    }

    header:after {
      content: '';
      width: 460px;
      height: 15px;
      background: url(images/intro-div.svg) no-repeat center;
      display: inline-block;
      text-align: center;
      background-size: 70%;
    }

    h1 {
      color: #fff;
      font-size: 50px;
      font-weight: 400;
      letter-spacing: 0.18em;
      text-transform: uppercase;
      margin: 0;
    }

    h2 {
      color: #fff;
      font-size: 24px;
      font-style: italic;
      font-weight: 400;
      margin: 0 0 30px;
    }

    .nowplaying {
      font-size: 120px;
      line-height: 1;
      color: #eee;
      text-shadow: 0 0 5rem #028ae9;
      transition: all .07s ease;
      min-height: 120px;
    }

    .keys {
      display: block;
      width: 100%;
      height: 350px;
      max-width: 880px;
      position: relative;
      margin: 40px auto 0;
      cursor: none;
    }

    .key {
      position: relative;
      border: 4px solid black;
      border-radius: .5rem;
      transition: all .07s ease;
      display: block;
      box-sizing: border-box;
      z-index: 2;
    }

    .key:not(.sharp) {
      float: left;
      width: 10%;
      height: 100%;
      background: rgba(255, 255, 255, .8);    
    }

    .key.sharp {
      position: absolute;
      width: 6%;
      height: 60%;
      background: #000;
      color: #eee;
      top: 0;
      z-index: 3;
    }

    .key[data-key="87"] {
      left: 7%;
    }

    .key[data-key="69"] {
      left: 17%;
    }

    .key[data-key="84"]  {
      left: 37%;
    }

    .key[data-key="89"] {
      left: 47%;
    }

    .key[data-key="85"] {
      left: 57%;    
    }

    .key[data-key="79"] {
      left: 77%;    
    }

    .key[data-key="80"] {
      left: 87%;    
    }

    .playing {
      transform: scale(.95);
      border-color: #028ae9;
      box-shadow: 0 0 1rem #028ae9;
    }

    .hints {
      display: block;
      width: 100%;
      opacity: 0;
      position: absolute;
      bottom: 7px;
      transition: opacity .3s ease-out;
      font-size: 20px;
    }

    .keys:hover .hints {
      opacity: 1;
    }

const keys = document.querySelectorAll(".key"),
  note = document.querySelector(".nowplaying"),
  hints = document.querySelectorAll(".hints");

function playNote(e) {
  const audio = document.querySelector(`audio[data-key="${e.keyCode}"]`),
    key = document.querySelector(`.key[data-key="${e.keyCode}"]`);

  if (!key) return;

  const keyNote = key.getAttribute("data-note");

  key.classList.add("playing");
  note.innerHTML = keyNote;
  audio.currentTime = 0;
  audio.play();
}

function removeTransition(e) {
  if (e.propertyName !== "transform") return;
  this.classList.remove("playing");
}

function hintsOn(e, index) {
  e.setAttribute("style", "transition-delay:" + index * 50 + "ms");
}

hints.forEach(hintsOn);

keys.forEach(key => key.addEventListener("transitionend", removeTransition));

window.addEventListener("keydown", playNote);

This Pen is owned by Caroline Gabriel on CodePen.

See more by @gabrielcarol on CodePen

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External JavaScript

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