elgar's oratorios?

I'm researching Elgar's Dream of Gerontius in the context of British oratorio tradition and am reading Charles McGuire's Elgar's Oratorios.

There's this passage in which he quotes Jurij Lotman, a linguist:

[The artistic text] transmits different information to different readers in proportion to each one's comprehension; it provides the reader with a language in which each successive portion of information may be assimilated with repeated reading. It behaves as a kind of living organism which has a feedback channel to the reader and thereby instructs him.

The concept of "language"... will encompass: a) natural languages (for example, Russian, French, Estonian, Czech); b) artificial languages - the languages of science (the metalanguages of scientific descriptions), the languages of conventional signals (road signs, for example), and so on; c) secondary languages (secondary modeling systems) - communication structures built as superstructures upon a natural linguistic plane (myth and religion, for example). Art is a secondary modeling system.

And then McGuire sort of maps this kind of critical language onto musical texts through a series of translations, which are also part of Lotman's critical theory. This is all kind of bending my mind at the moment. Cool.