el" href="classRtMidi.html" title="An abstract base class for realtime MIDI input/output.">RtMidi</a> callback function. </p>
<dl class="params"><dt>Parameters</dt><dd>
  <table class="params">
    <tr><td class="paramname">timeStamp</td><td>The time at which the message has been received. </td></tr>
    <tr><td class="paramname">message</td><td>The midi message. </td></tr>
    <tr><td class="paramname">userData</td><td>Additional user data for the callback.</td></tr>
  </table>
  </dd>
</dl>
<p>See <a clas