The only good songs do is make the Stage Creator have a larger variety of tracks to choose from... Good thing I use stage creator! Thanks for the tip. :)
Only 1 song left..... (How do I know? I see the last CD at the challenges and the CD`s don`t appear in Brawl anymore)
I already did this when I first got the game. Here's an exploit! Take R.O.B. and use him on the Zelda level with the bridge that explodes. When the bridge starts to rebuild, jump into it and use your final smash. R.O.B. will be pushed out of the bridge when you do. He will now be invincible, and never stop using his final smash. Glitch found by ME!
How you know when you have all songs: Doublex-Zero, when you unlock all CD's you should get a message, and a trophy ^^