 </dl>
  <h4 id="envelope"><a href="#envelope" class="header-anchor"
  aria-hidden="true">Envelope</a></h4>
  <dl>
  <dt>Envelope Wave</dt>
  <dd>
  <p>The waveform of envelope wavetable.</p>
  <p>Wavetable is shared between all voices.</p>
  </dd>
  <dt>Time [s]</dt>
  <dd>
  <p>Duration of envelope from the start of a note.</p>
  <p>When envelope reaches the end, all the modulation amounts becomes
  0.</p>
  </dd>
  <dt>Wave Interp.</dt>
  <dd>
  <p>Envelope wave form interpolation method.</p>
  <p>This p