<svg xmlns="http://www.w3.org/2000/svg">
  <foreignObject x="0" y="0" width="100px" height="100px">

    <!-- lime background -->
    <div xmlns="http://www.w3.org/1999/xhtml"
         style="background:lime; width:100%; height:100%;">
      <!-- Use an unrecognized media type, so that if we're honoring plugins,
           the "download plugin" placeholder will be shown. -->
      <embed xmlns="http://www.w3.org/1999/xhtml"
             src="data:audio/hahaThisIsntReallyAFormat,"
             width="100px" height="50px"/>
      <!-- Also try a possibly-recognized media format, for completeness. -->
      <embed xmlns="http://www.w3.org/1999/xhtml"
             src="data:audio/wav,"
             width="100px" height="50px"/>
    </div>
  </foreignObject>
</svg>