Throughout rock's long history, it's been common practice for an artist to cover a song that was a hit for someone else. But what about those covers of a song that's more obscure? We put the spotlight on 35 Famous Records You Probably Didn't Realize Were Covers below.

First, let's define what constitutes a cover. By our rules for this list, we've mostly stuck to songs that were commercially available -- as opposed to a songwriter's demo -- when someone covered it. So, UB40's version of Neil Diamond's "Red Red Wine" is a cover because it came out on Diamond's second album, but the Monkees' recording of "I'm a Believer" is not a cover, because Diamond wrote it when he was working as a Brill Building songwriter and the Monkees were the first to release it.

That said, there are two recordings, by Heart and the Steve Miller Band, where the original versions didn't come out until afterward, but because they matched the covering band's aesthetic so closely, we were surprised to learn that they weren't written by them.

We've also stayed away from covers where the original is pretty much familiar to music fans, like the Beatles' hit rendition of the Isley Brothers' "Twist and Shout" or Jimi Hendrix's revolutionary interpretation of Bob Dylan's "All Along the Watchtower." And then there are many tracks by Led Zeppelin that reworked old blues numbers and tried to pass them off as traditional songs with new arrangements by Jimmy Page.