Originally Posted by silverwick

This, according to the Beach Boys onwards, was the first album that began a genre later labelled Progressive music. I do not think anyone who knows a reasonable amount about music would dispute that.
Along with many other things we have the Beatles to thank for Pink Floyd, Genesis, Yes, King Crimson, Mike Oldfield, Jethro Tull, ELP, Camel, Kate Bush, Focus, Opeth and Porcupine Tree.
For reference I refer everyone to 'The 50 albums that built progressive'.