Rhythmbox

Rhythmbox's database is an XML file located at $HOME/.local/share/rhythmbox/rhythmdb.xml

<?xml version="1.0" standalone="yes"?>
<rhythmdb version="2.0">
  <entry type="song">
    <title/>
    <genre/>
    <artist/>
    <album/>
    <location>file:///Music/...</location>
    <!-- snip -->
  </entry>
</rhythmdb>