Mine is definitely Rusyn and is the product of a split with a Ruthenian BCC not too far away. We're not one of the Russian ones that came in later over the calendar. I don't know the whole history of how things work or started, but I know that our parish basically works like this.

We have both cantors and a choir. Prostopinije is used in every single service no matter what. If the choir is singing, then as you say Prostopinije will be used for the days Tropar, Kondak and Prokeimena, along with any other special hymns used. The choir will sing things like the hymns from the fixed part of the liturgy (the Trisagion for instance as you pointed out). On some Sundays if the choir director is gone, and generally all throughout summer the whole thing will be led by the Cantors using Prostopinije. Typically when we use Slavonic (aside from greetings), it will be something sung by the choir. Where the music the choir uses came from seems to be unknown by everyone, including the choir director because I asked her. I definitely don't think it came from the diocese. I do recognize some of the settings however from things I have heard in churches that use Great Russian music (i.e the OCA and actually the Antiochians).

I guess in a sense it's not good that we seem to mix, but by the same token our choir sings beautifully and the choir director does a very good job. So we get some of two different traditions, and I know Prostopinije is not going to disappear in our parish.

You mean byzcaths and Eastern orthodox use the same hymn books or music? what keeps them apart?

Eddie

Some disagreements on some fundamental aspects of the faith.

I would assume it's similar to why Roman Catholics and Protestants are still apart, though many R.C. parishes now use Protestant hymns in their worship.

Ed the ACROD and Ruthenian Byzantine Catholic church both use prostopinije/Carpatho-Plain chant. The differences are in dialects, which basically amount to certain notes being a third-step different. The Ruthenian Byzantine Catholic Church uses the (spelling warning) Mukachekavo dialect and the ACROD uses the Presov dialect. Both the Byzcath and the ACROD are very similiar in tradition since the ACROD left the Ruthenian Byzcath church in the late 1930's and returned back to the Ecumenical Patriarch.

Wasn't there supposed to be some difference with the outlook of the clergy from these two diocese?

Both the Ruthenian Metropolia and the ACROD use what ever pronounciation of Slavonic the founders of each parish used. Some are from the Prjashev area and use a soft sounding nyni(nen knee) while those from Uzhoord-Mukachevo us a harder nyni sound (nahw knee). So both jurisidictions use both, some even use a Galiciany pronounciation if there were Galician Rusyns in their parish.

Ungcsertezs (I use my Baba's softer Prjashev prounciation)

I know the dialect thing... who'd've thought it comes out in music? Brits sound American when they sing, usually, so I figured music voided dialect.

Orthodox Pyrohy has become a music scholar at last! "third-step"... I'm so proud of you, anam chara!

Being a good revised Byzantine Catholic, I just can't catch onto some of the ACROD melodies. It's like, they're just a BIT off somehow. Like the 1st "Lord have MERcy" in ACROD is just a bit strong on that "mer" part.

However, since I seem to attend ACROD almost half as frequently as I do ByzCath (which say a lot, believe me), I'm starting to not even notice the differences, I just adapt. In Linguistics, we call that "switching registers." Pyrohy will tell you that means I'm THAT much closer to embracing Orthodoxy, no doubt. At the least, my brother will say I can't be both Orthodox and Catholic at the same time! Just kidding, but you DO say that a lot these days.

Hehe Domilsean, you're my brother no matter if you're a Christian of the True Faith or a Orthodox Christian, or if you eat Pyrohi or the True Faith or Orthodox Pyrohis. Note to the casual observer, you have had to have been around to get the pierogie joke.
I'll call you know and sing to ya so you get those ACROD melodies correct. After all the ol' anam chara needs to be able to multi-task his protopinije-ism. Want me to tell you that again about the Orthodox thing?

Remember too that Metropolitan Orestes of thrice blessed memory attended seminary in Presov. If memory serves me his co-founding fathers also were from the Presov school. So the Presov dialect became standard in the ACROD.