I used to see these guys whenever they played NY or Boston starting with Aqualung and up through the Stormwatch tour. I think that the place to start understanding Tull is not Tull at all, but Rashaan Roland Kirk, the primary influence on Ian Anderson's flute playing. The over blowing, the talking, the very structure of the solos all add up to Anderson channeling Kirk. So, the real place to start is Kirk's album, "I Talk With The Spirits" on Mercury/Limelight LM/LS86008. Listen to the first track, "Seranade To A Cukoo" now it's time to put on "Bouree" by Tull. Eureka! It all comes into clear focus. I would then work through "This Was" and "Stand Up" followed by "Benefit". It's too bad that you can't see the stage show for "Thick As A Brick" as it is a master stroke, visually, at least, their high water mark, and clearly conceived as an audio/visual experience.