[I LOVE MY DAUGHTERS]

Originally Posted by Swors-k

I REALLY hope I don't have to go back through it all on normal just to get one fucking song. :/

You do have to do it on normal. I believe it is somewhere in babylon or playing against babylon or something. Find all the ones that say pluto and play them, One of them will unlock it for you.
You dont have to do the entire game, just go through the chapters and check, or find out online, im sure its posted somewhere.

When I went through, I would always look on normal for songs I didnt have unlocked, and play them. Sometimes they unlocked, sometimes they didnt. I almost think that you must play certain songs X number of times in SMM before they unlock.