Hello,
I submit a new patch for including a popular format among musicians: ABC notation.
Like for the txt2tags one (which is also included in this patch), there is only the tagmanager part at the moment.
Abc is praised by many linux users and there are several command line tools for manipulating it:
http://abcnotation.com/software.html#commandline
It's already included into kate and jed: http://abcplus.sourceforge.net/#JedABC
With the tagmanager in geany, it makes it really conveniant to browse tunes books this way because you can select the tune by number or title.
try for example: http://concertina.datenbrei.de/downloads/steierm1.abc