The Tanglewood concert is very exciting; 1970 Jethro Tull delivering the customary blinder, including the beta version of My God which would later turn up somewhat squished on Aqualung. Watch them doing it at the Isle of Wight the same year: http://www.youtube.com/watch?v=dh0woT7NkKI. Flute solo notwithstanding (always sub-Rahsaan) I'd say that hits the spot.

I love the first three albums, maybe 30% of Aqualung, and Thick as a Brick is one of my all time favourite albums, after which maybe they should have called it a day. What happened to IA's voice that by Songs of the Wood it had become a nasal whine? And who was listening to Tull in 1977 anyway? Shame that the exciting folk influences very much in evidence throughout Stand Up, Witch's Promise etc. had become dreary prog bombast thereafter.