Data not directly related to a song, but useful for debugging and other
purposes. Other items include modification time and the name of the
application used to create the song.
song properties
Additional information about a song. There can be author name, copyright
information, publisher, release date, etc.
theme
Clasifying songs to various groups along suitability.
transliteration
Transcription of text in one alphabet to another while retaining
the language it was written in. For instance writing Chinese characters
using latin.