I have this theory and I would like you to comment on it. The relation between Jethro Tull´s Thick as a Brick and A Passion Play is the same that Yes´s Close to the Edge and Relayer.
Look it like this, both Thick and Close are the masterpieces from both bands ( not the only masterpieces, but you can say that they are wheater you like them or not the bests they have made), but then there are A Passion and Relayer, which many find more interesting.
Then there are the same structure in both, Jethro Tull´s 2 long epics and Yes one monster epic and 2 shorter songs of which one is pure guitar and the other king like a clasic piece.
And finally both A passion and Relayer are both more complex than Thick and Close...and both came out after...
What do you say?...I also like Realyer and A Passion Play mose than Close and Thcick as a Brick...