Van Der Graaf Generator were difficult to most listeners. They are not "tight" in the way King Crimson or Genesis are known for. They were way more punk and experimental in their approach to "progressive" music of the time. Jazz influenced in theory only, not in the academic way, say, Henry Cow or Gentle Giant were. There are no frolicking elves and faeries in Van Der Graaf music. This is why they rock a thousand times more than their peers.
Vital is the only official live album of the 70s released by the mighty Van Der Graaf (they dropped the Generator by this time) and it is a fucking ripper. Not ripping in the sense of Thin Lizzy - Live and Dangerous per se, but more in the way of Sleep's Holy Mountain or something. Singer/main songwriter/keyboardist Peter Hammill is brilliant at making music that's both beautiful and horrific at once and he honed that skill perfectly within the group of insanely talented musicians in VDGG. This release highlights my favorite aspects of their music. The contrast between Hammill's angelic and demonic vocals, disgustingly distorted thumping bass, intense drumming and David Jackson's sax. Yes sax. Don't be scurred. It works.
This is prog at it's best. It's absolutely madness. Play loud.