Jethro Tull's second album-length composition, A Passion Play is very different from - and not quite as successful as - Thick as a Brick. Ian Anderson utilizes reams of biblical (and biblical-sounding) references, interwoven with modern language, as a sort of a rock equivalent to T.S. Eliot's The Wasteland. As with most progressive rock, the words seem important and profound, but their meaning is anyone's guess ("The ice-cream lady wet her drawers, to see you in the Passion Play..."), with Anderson as a dour but engaging singer/sage (who, at least at one point, seems to take on the role of a fallen angel). It helps to be aware of the framing story, about a newly deceased man called to review his life at the portals of heaven, who realizes that life on Earth is preferable to eternity in paradise. But the music puts it over successfully, a dazzling mix of old English folk and classical material, reshaped in electric rock terms. The band is at its peak form, sustaining the tension and anticipation of this album-length piece across 45 minutes, although the music runs out of inspiration about five minutes before it actually ends.
(allmusic.com/album/a-passion-play-mw0000036413)

Album recorded and mixed in the analog domain - AAD. That is, a minimum of digital processing.
A=Analog. D=digital. The first letter stands for how the music was recorded. The second letter for how it was mixed. The third letter stands for the format (all CD's will have D as the last letter).