for each voice. When index reaches the value
  set at <code>Cycle At</code>, it goes back to 0. Now, we set
  <code>Cycle At</code> to 1.</p>
  <pre><code>0.1, 0.2, 0.1, 0.2, ...</code></pre>
  <p>Then we send note number 60 to the synthesizer. The pitch for each
  voice becomes following.</p>
  <pre><code>60,                         // 60
60 + 0.1,                   // 60.1
60 + 0.1 + 0.2,             // 60.3
60 + 0.1 + 0.2 + 0.1,       // 60.4
60 + 0.1 + 0.2 + 0.1 + 0.2, // 60.6
...</code></pre>
  <p>Belo