Song Schema with XLink Support

<xsd:schema xmlns:xsd="http://www.w3.org/2000/10/XMLSchema"
  xmlns="http://ibiblio.org/xml/namespace/song"
  xmlns:xlink="http://www.w3.org/1999/xlink"
  targetNamespace="http://ibiblio.org/xml/namespace/song"
  elementFormDefault="qualified"
  attributeFormDefault="unqualified"
>
 
  <xsd:import namespace="http://www.w3.org/1999/xlink" 
              schemaLocation="xlink.xsd"/>

  <xsd:complexType name="PhotoType">
    <xsd:complexContent>
       <xsd:restriction base="xsd:anyType">
         <xsd:attributeGroup ref="XLinkAttributes"/>
         <xsd:attribute name="ALT"    type="xsd:string"/>
         <xsd:attribute name="WIDTH"  type="xsd:nonNegativeInteger"/>
         <xsd:attribute name="HEIGHT" type="xsd:nonNegativeInteger"/> 
      </xsd:restriction>
    </xsd:complexContent>
  </xsd:complexType>

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

  <xsd:complexType name="SongType">
  
    <xsd:element name="TITLE"     type="xsd:string" 
      minOccurs="1" maxOccurs="1"/>
    <xsd:element name="PHOTO"     type="PhotoType"  
      minOccurs="0" maxOccurs="1"/>
    <xsd:element name="COMPOSER"  type="xsd:string" 
      minOccurs="1" maxOccurs="unbounded"/>
    <xsd:element name="PRODUCER"  type="xsd:string" 
      minOccurs="0" maxOccurs="unbounded"/>
    <xsd:element name="PUBLISHER" type="xsd:string" 
      minOccurs="0" maxOccurs="1"/>    
    <xsd:element name="YEAR"   type="xsd:year" 
      minOccurs="1" maxOccurs="1"/>
    <xsd:element name="ARTIST" type="xsd:string" 
      minOccurs="0" maxOccurs="unbounded"/>
    
  </xsd:complexType>

</xsd:schema>