This is pretty much a mashup of a bunch of different things. I'm not immediately sure what the song is at the beginning. Then there's something else I don't recognize. Then it goes into the melody of Der Voghormya (Lord Have Mercy), which is from the Divine Liturgy. Then there's some totally unrelated chanting in completely different keys...
Long story short, this is something off of a contemporary music CD that someone has used to essentially created a collage out of a bunch of different things. There's elements from an ensemble called Akn, which is working to revive ancient, pre-Western influenced Armenian liturgical music and traditions.http://www.akn-chant.org/en
As for the words at the beginning, my Armenian is really rusty right now, but the best I can tell, it starts something like:
A multitude of people have witnessed today the radiant light of the holy cross (or, the light of the holy cross, radiant...)