x.html">back</a>
    </p>
    <div class="waveform-container">
      <canvas class="waveform" height="40"></canvas>
    </div>

    <div class="trace-container">
      <code class="trace-binary">0b00000000</code>
      <code class="trace-text"></code>
    </div>
    <div class="spectrum-container">
      <canvas class="spectrum" height="150"></canvas>
    </div>

    <div id="piano">
    </div>

    <h2>config</h2>
    <label for="waveform">waveform:
    <select id="waveform">
      <option value="sine">sin