Why does the Catholic Church sing Kyrie Eleison when its a product of the Eastern Ort

As an Eastern Orthodox christian I have always found it bizarre that the Roman Catholic church would use the phrase Kyrie Eleison in their masses. What's up with that? Latin wasn't good enough? It's certainly better then medieval Greek. It flows better, its easier on the tongue, and harmonious in the ears. So why bother? Did some crusader centuries ago stumble into the Hagia Sophia on the way to Jerusalem and say "Cool! Lets sing that!"?

The pope secretly loves Mister Mister.

http://www.youtube.com/watch?v=dOq9v4fAEo0

http://www.newadvent.org/cathen/08714a.htm

Have you ever sung the Kyrie? It's beautiful. It's a remnant of Roman Catholicism's ties to Greek orthodoxy, and I'm glad we still recognize those ties.

Well, the New Testament was written in Koine Greek, so I think both the Orthodox and Latin rite Catholics have equal claim to it. I personally think it is beautiful, and it is one of my favorite parts of the Mass. I love that our Masses have all the sacred languages-Latin, Greek, and some Hebrew.

Umm, you realize that "Christian" comes from Greek, not Latin. Right?

Because it's beautiful to hear and to say.

That, and our two Churches are very closely linked. I hope that in my lifetime we will see them finally re-unite.

The Western Liturgies were originally in Greek before the mid 3rd cent in North Africa from which Latin Masses spread to Italy and the rest of the West.
A number of popes were Greek and one put the 9 fold Kyrie in instead of the whole Opening Etenia

Both are Christian Churches, so why not?

Do you know that, after the Second Vatican counsel. When the Latin mass were replaced by the local languages. The Church asked that the Kyrie would be the only part of the Latin that should be remained but it too was replaced by the local language. I am glad that the Latin mass is making a come back!!!

It is from the undivided church of the first millennium, centuries before the crusades. I this it's beautiful that the same phrase in used in many nations. There are other Greek works in the RC mass, for example 'Eucharist' means thanksgiving in Greek, from 1 Corinthians11:24.