Candidates for a photo gallery of Altered Album Covers must have a resume topped by at least one offense – be that death, nudity and general ickiness.

Still, the wonder is that it ever happened in the first place. After all, album covers are the gateway to the music found inside, a crucial part of the listening experience. And just as songs are pored over by the artists who make them, album covers – you'd think – are meticulously designed to reflect the theme of the project.

But sometimes those original ideas are shot down, even after the records reach the hands of fans.

Our list of 20 Altered Album Covers includes some of rock's biggest names -- from the Beatles and the Rolling Stones to Guns N' Roses and Jimi Hendrix to David Bowie and Van Halen.

What was altered, and why? Sometimes the albums in question are obviously in need of some sort of change to make them acceptable for mainstream tastes. But just as often, some changes will leave you scratching your head.

And it's been going on forever. There are albums from the '60s, '70s, '80s and beyond featured here. Artists always liked to stir up things ... and the Man always tried to keep them down. That's not to say some of these changes weren't made for the better (we can think of one supergroup LP cover that, yeah, probably wasn't the smartest move the first time around).