In the 1970s, design duo Hipgnosis were given free reign to create some of the most expansive album artworks of all time.

Explore iconic ‘70s female singers who defined a decade. Discover their timeless music, unforgettable voices and lasting ...

But that doesn't mean these albums aren't good or weren't even popular with the most passionate fans. These are the most underrated '70s rock albums that we still can't believe didn't sell more.

Now, that surely covers a wide musical ground, from classical music to vaudeville, you name it, but also Yet, with all the big names that can be found on the list of great art rock albums ...