per) / (Tempo Lower)</code> is <code>1/1</code>.
  <code>1/4</code> synchronizes to 1 beat when time signature of
  <code>4/4</code>. Note that <code>Rate</code> multiplies the sync
  interval.</p>
  <p>Following is the equation to calculate sync interval.</p>
  <pre><code>syncInterval = (Rate) * (Tempo Upper) / (Tempo Lower);</code></pre>
  </dd>
  <dt>Tempo Lower</dt>
  <dd>
  <p>Denominator of sync interval.</p>
  <p>Note that <code>Rate</code> multiplies the sync interval.</p>
  </dd>
  <dt>Rate</dt>
  