oRoll or GuidoMidi2PianoRoll </td></tr>
    <tr><td class="paramname">width</td><td>the width on which piano roll will be drawn (-1 to set the default width : 1024) </td></tr>
    <tr><td class="paramname">height</td><td>the height on which piano roll will be drawn (-1 to set the default height : 512) </td></tr>
    <tr><td class="paramname">dev</td><td>the device on which piano will be drawn </td></tr>
  </table>
  </dd>
</dl>
<dl class="return"><dt><b>Returns:</b></dt><dd>a Guido error code (returns guido