From:  http://www.cifranet.org/xml/chordml.dtd
Date:  1999-01-14
By:    Gustavo Frederico

-----------------------------------------------------------------

<!ELEMENT ChordML (copyright, textref? , (lyrics, sugend?)+)>
<!ATTLIST ChordML
   title CDATA #REQUIRED
   version CDATA #IMPLIED
   author  CDATA #IMPLIED
   translator CDATA #IMPLIED
   idiome CDATA #IMPLIED>
<!ELEMENT copyright     (#PCDATA) >
<!ELEMENT textref     (#PCDATA) >
<!ELEMENT a   (#PCDATA) >
<!ATTLIST a  
 c CDATA #REQUIRED
 al CDATA #IMPLIED > <!-- alternative -->
<!ELEMENT lyrics  (#PCDATA|a)*>
<!ELEMENT sugend (#PCDATA) >

<!-- sample -->

<?xml version="1.0"?>
<!DOCTYPE ChordML SYSTEM "http://www.cifranet.org/xml/chordml.dtd">

<ChordML title="If you're happy and you know it" version="standard"
 author="John Doe" translator="Zorro" idiome="English">

<copyright>(c)1999 Mucrosoft</copyright>

<textref>Rejoice, again I say: rejoice.
</textref>

<lyrics>
If you're <a c="G"/>happy and you know it clap your <a c="D">hands</a>

If you're happy and you know it clap your <a c="G">hands</a>

etc

</lyrics>
</ChordML>