Then again perhaps that set off a false equivalence that somehow post 1976 music is equal to 63-1976 when we all know that was the peak of rock music and it all went downhill from there
So if 90 is from 63 to 76.
Then perhaps half of that (so 45) would be fairer from 77 to present (implying that it's half as important as the previous era.
I also thinking to George list perhaps I should add an example of canterbury prog to the list like In the land of grey or pink or If I Could Do It All Over Again I'd Do It All Over You (I prefer the latter but I know the former is more well-respected)
If there was Van Der graaf generator there, there really should be something from the cantebury scene. hell maybe an italian prog album like Darwin or Per Un Amico or Quebecan prog with Harmonium should be there but perhaps that's taking the artrock/prog representation too far