Quote: Gordon Bennett @ November 24 2012, 7:47 PM GMTThey laid the groundwork for almost everything that followed: power pop, prog (A Day In The Life), hard rock (Helter Skelter), "music hall pop" (when I'm Sixty Four)...
There's no doubting their influence, but I think it's important to realise they were part of a wider scene, rather than sole pioneers. For example, I've heard McCartney say he wrote Helter Skelter after reading that The Who had just released the most raucous song ever written, and certainly there was stuff around that sounded much like hard rock before it (like Blue Cheer).