act to cymbal independent to wavetable oscillator.</p>
  <p>TODO プリセットの紹介</p>
  </dd>
  <dt>Gain [dB]</dt>
  <dd>
  <p>Oscillator output gain.</p>
  </dd>
  <dt>Attack [s], Decay [s]</dt>
  <dd>
  <p>Oscillator AD envelope attack time and decay time.</p>
  <p>When <code>Decay</code> is short, increasing <code>Attack</code>
  almost doesn’t change the sound.</p>
  <p>Note that the value is not exact. It converts to filter cutoff
  frequency.</p>
  </dd>
  <dt>Octave, Semitone</dt>
  <dd>
  