-O-=Original song, i.e.: All me.
-A-=Arrangement of song, i.e.:written by someone else, changed by me.
-L-=Song with lyrics, lyrics included!
-E-=Experiment song, song that I tried to accomplish something with by screwing around.

If you can't find the vocal line in a song with lyrics, just follow the notes by syllables.

ex: the ci-ty lights come on and im shoot-in' down the street (each syllable is a different note).

If the song isn't playing, it's cause it hasn't loaded yet. I can't manage to get a loading bar on them yet, but I'll figure it out yet...