How different is the chant in the east and where can we find information on the theology of the icon? I'm one who does believe that east and west need to be joined, but that there is a lot to learn about each other and a lot of minds to convince first.
The music of the Liturgy is a recurring subject at Orthodox parishes among some converts.
It's plain and simply a recurring theme among Catholics. With all luck, under BXVI a lot of the crap will fall to the wayside.
Interesting observations, and now you've made me learn some things.
The RC regs on liturgical music have been deliberately confused by a bunch of wonk/termites (I'll not go into the rest of their personal, ah, problems) since VatII; but if one goes back to Pius X's writings on the topic, one gets a better sense of what prevailed from at least (circa) 1500-1965. B-16's writings are closely aligned to the work of Pius X.
Prior to VatII, there was a distinction between the 'High' (sung) Mass and the 'Low' (spoken) Mass--that no longer exists as it was known.
During the Low Mass, there was almost no singing, although there could be a hymn prior to (and after) the Mass. In the High Mass, the Proper Chants were sung, as were parts of the Ordinary of the Mass. The Propers were most often sung in Gregorian Chant OR in psalm-tone, and like the music Agrarian refers to, the Propers had a thematic unity with the rest of the readings of the Mass. In shorthand, it was 'tightly wound.'
However, in addition to the Ordinary and Propers, the choir could also sing voluntary motets which were not necessarily thematically-consistent with the Propers/Epistle/Gospel. Some of the motets utilized texts from Scripture; others used particular prayers (e.g., an Ave Maria or Panis Angelicus, respectively.)
Hymnody was restricted to popular devotions--not Masses. NO language other than Latin was permitted during the course of a Mass. The vulgar was allowed before or after a Mass ONLY.
The Bugnini/Weakland implementing commission made two significant changes: they erased the difference between the 'High' and 'Low' Mass, and allowed hymnody to be used during Mass, in the vulgar. IMHO, these changes must be examined carefully in light of B-16's work on Sacred Music (a glimpse of which can be inferred from the posted thread-head.)
Allowing hymnody has led to an even LESS 'tightly wound' schematic of worship than was present until 1965. The vast majority of hymns familiar to Catholics were not necessarily based on themes integral to various liturgies--rather, they were seasonal, Marian, or Eucharistic. These three classes, then, HAD to serve. Ironically, while allowing 'popular participation' the richness of each Sunday's theme-scheme was truncated, because current praxis does NOT require the priest (or anyone else) to sing or even recite the Propers--the Introit, Offertory, and Communion versicles. And because it is not required, it is not done, period.
So we have 'given a haircut' to the Mass; where the hair used to be specific and ornamental, it is now a military 'butch.' The best the iconoclasts can say is that 'there is still some hair there.'
Without extensive comment, the remaining hair has also taken on some characteristics which are unsettling--the equivalent of very bad purple or red-dye jobs...
I think that there is much to be said which is positive about the post-1500 well-composed Mass Ordinaries and voluntary motets. It is legitimate to argue that many of these demonstrate the Church's "universality," as a variety of cultural influences were 'baptized' into the service of the Church (for example, Durufle's 4 Motets, compared to Mozart's 'Ave Verum.') But as Ag. points out very well, the situation today is almost 'no bounds;' and it is confusing.
The music of the Liturgy is a recurring subject at Orthodox parishes among some converts. They say they miss the hymns they sang in their pre-Orthodox days at church. I don't doubt that one bit, but as we explain to them, the designated hymns of the Divine Liturgy are as much part of the Liturgy as, say, the Our Father or the Antiphons. They are not something which changes with the weather or at the whim of a priest."
I actually have a spare moment between things to write. But I, in distinction to some converts, do not miss the hymns of my latter days. There is a superficiality in the warp and woof of them. Scripture tells us to teach and admonish one another in hymns (COl.3:16 ?) We could well say in addition to "the rule of prayer is the rule of faith" the rule of hymns is the rule of faith" Every antiphon is orchestrated providentially by the Spirit of God.