Led Zeppelin is classic rock. So are Mötley Crüe and Ozzy Osbourne. But what about U2 or Nirvana? As a child of the 1990s, I never doubted that any of these bands were classic rock, even though it may be shocking for many to hear. And then I heard Green Day’s “American Idiot” on a classic rock station a few weeks ago, and I was shocked.
It was my first time hearing a band I grew up with referred to as “classic rock.” Almost anyone who listens to music over a long enough period of time probably experiences this moment — my colleagues related some of their own, like hearing R.E.M. or Guns N’ Roses on a classic rock station — but it made me wonder, what precisely is classic rock? As it turns out, a massive amount of data collection and analysis, and some algorithms, go into figuring out the answer to that very question.
FiveThirtyEight breaks down the math of what exactly defines a musical act as “classic rock”.