I don't think you should list what powers you would choose for the song. After all you will probably get someone else's song and have a interprate the song different than the person who listed the song. I just feel it makes everybody a little less creative with their power choice.
Also I only have 2 songs chosen now.
Bolded the first part, since you're pretty spot on with that, just post the songs, the powers will come later.
As for the latter part, I have to admit, I didn't really think the whole limit to songs thing through, the more songs that are posted, the larger a pool of songs there are to chose from, which means we'll likely have a larger variety of powers.
With that in mind, I'm relaxing the upper limit for how many songs you may post, but I'll stick to a 2 songs minimum per player.