Song Schema with XLink Support

<?xml version="1.0"?>
<xsd:schema xmlns:xsd="http://www.w3.org/2001/XMLSchema"
  xmlns:xlink="http://www.w3.org/1999/xlink"
  targetNamespace="http://ibiblio.org/xml/namespace/song"
  elementFormDefault="qualified"
>

  <xsd:import namespace="http://www.w3.org/1999/xlink"
              schemaLocation="xlink.xsd"/>

  <xsd:element name="SONG" type="SongType"/>

  <xsd:complexType name="PhotoType">
    <xsd:attribute name="WIDTH"  type="xsd:positiveInteger"
                   use="required" />
    <xsd:attribute name="HEIGHT" type="xsd:positiveInteger"
                   use="required" />
    <xsd:attribute name="ALT"    type="xsd:string"
                   use="required" />
    <xsd:attribute ref="xlink:type"/>
    <xsd:attribute ref="xlink:href" use="required"/>
    <xsd:attribute ref="xlink:actuate"/>
    <xsd:attribute ref="xlink:show"/>                 
  </xsd:complexType>

  <xsd:complexType name="SongType">
    <xsd:sequence>
      <xsd:element name="TITLE"     type="xsd:string"/>
      <xsd:element name="PHOTO"     type="PhotoType"/>
      <xsd:element name="COMPOSER"  type="xsd:string"
                   maxOccurs="unbounded"/>
      <xsd:element name="PRODUCER"  type="xsd:string"
                   minOccurs="0" maxOccurs="unbounded"/>
      <xsd:element name="PUBLISHER" type="xsd:string"
                   minOccurs="0"/>
      <xsd:element name="YEAR"      type="xsd:gYear"/>
      <xsd:element name="ARTIST"    type="xsd:string"
                   maxOccurs="unbounded"/>
    </xsd:sequence>
  </xsd:complexType>

</xsd:schema>