Time ago I was looking into the archives, I found an album which name I don't remember by a band I don't remember either. It was a metal opera, and the only album by the band, which I remember had a great - good score.
I also remember the band playing live in theaters, like an actual opera.

If you could help me find it i'd appreciate it.

Edit: I'm pretty sure it was on the archives, so it wasn't Aeterno Elementum.

You may be looking for this: http://www.metal-archives.com/bands/Abydos/25679

I think it was only played in one place, but for several times. I watched it live, mainly because of the music, but I also thought it was well acted.

Well thanks CoF, unfortunately that's not the band. Not bad tough.
It was a little more in the 'gothic - symphonic' side of music.

Well, Xystus doesn't have one album only, but it was the first thing that popped to my mind. Namely: http://www.metal-archives.com/albums/Xy ... rio/197217

YES! That's it. Such a weird name to remember haha. Thank's Deviante. (Thought they had only one album, my bad)