Instrumental Works collects ten of The Alan Parsons Project's best musical pieces and acts as a wonderful journey through some of this group's most innovative material. Although famous for his concepts, Alan Parsons is equally renowned for his illustrious mood-invoking instrumentals that helped create atmosphere on all of his albums. These movements can easily be taken away from their master albums without losing their grandeur and charm, unlike his vocal works that act as pieces in a thematic puzzle and are better left within their conceptual domain. Both intricacy and subtlety are depicted here, with selections such as "I Robot," "Paseo de Gracia," and "Hawkeye." The all-encompassing "Mammagamma" from Eye in the Sky is wisely included as well, as is the peculiar "Urbania," one of the best tracks from Stereotomy. Noticeably missed, on the other hand, are two of their finest instrumentals in "Lucifer" and the short but stunning "Sirius." Even without these pieces, Instrumental Works spotlights Parsons' fine employment of musical diversity through his keyboard and guitar manipulation, while at the same time the music's simplicity is admirably felt. These selections are an entertaining jaunt across Parsons' non-vocal material.
(allmusic.com/album/the-instrumental-works-mw0000196611)

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).