<xs:element name="numberOfTracks" type="xs:int">
  <xs:annotation>
    <xs:documentation xml:lang="en">Specifies the number of audio channels</xs:documentation>
    <xs:appinfo>
      <identifier>http://w3id.org/meta-share/meta-share/numberOfTracks</identifier>
      <label xml:lang="en">number of tracks</label>
      <note xml:lang="en">In MS it's a controlled vocabulary (1, 2, 4, 8) but I think it's too much</note>
    </xs:appinfo>
  </xs:annotation>
</xs:element>