If one deals with lyrics in the Prog area it is noticeable that these often have a mythical character, which occurs in very different manifestations. Obviously the moods, which are produced musically in complex prog works, are strongly associated by their composers with myths and legends. The spectrum ranges from simple re-enactments or modifications of classical literary works from the fields of science fiction and fantasy to very abstract descriptions of the manifestations of the human psyche. In the Fantasy section, Tolkien's "Lord of the Rings" obviously left a deep impression. There is hardly any expression or name mentioned in this excellent narrative that has not yet to appeared as a group name or title of a Prog-song.
The musical variety typical for the classical Prog and the frequent alternation of unusual moods perceived by the listener is ideal to be used as program music for strange stories. This, however, often gives suck works a somewhat cheesy, pompous taste, which can sometimes become intolerable when the bombastic, deeply intentional pathos is combined with rather simple literary means.
The creators of such dubious works, however, have the advantage that the reception of Prog lyrics for majority of Prog listeners is confined to the associative level. Important for the reception is only secondary A logical or aesthetically consistent lyrical concept is usually less important than the temporal coupling of certain stimulus words sung by the lead vocalist with corresponding musical phrases, which can emotionally underline the textual statement.
In my opinion this is also the great, unfortunately only relatively rarely used chance of Prog, the musical interpretation of abstract, experimental lyrics. Through the combination with complex music, even very difficult lyrics can be consumed by the listener without effort, if the music pleases him. During repeated listening of the music, a gradual approach to the literary material can take place, which with high probability would have been denied to the listener with the "dry" reception of the lyrics. On the other hand, the music and the textual statement can intensify the meaningfulness of both elements.
As a very positive example, I would like to call Jethro Tull's "Thick as a Brick". Ian Anderson has succeeded here in a very successful combination of narrative, ironically humorous, very lyrical and experimental text forms, which at the same time is not taking itself so serious (which would otherwise a god idea for the entire Prog scene).