What is the hardest song to find?

Hey i think the hardest rock song ever would have to be angel of death by slayer

But more likely it's "Real Cool Time" by The Stooges. Listen to it, you will agree! It's the only song in the world that sounds like the Primordial Chaos of Azathoth, by H.P. Lovecraft. Listen to it Right Now on YouTube, you will agree!