Thank you very much for your time and honest opinion!
This article is a treasure! It helped me get a little closer to these Giants. And it also reinforced my opinion on a few points:

I then searched the Internet for additional information about "Allegro" and was unpleasantly surprised that there were not many results. This is the reason why I am still unable to provide you with enough music today.

And also:

"We weren't the ones who wanted to blend in with the mainstream, that played a bit of a bad joke later on, but we were never conventional rockers.", Yavor Kirin, lead vocalist

In the post above, I forgot to mention that the title of the song is "Of Glass", and in this article I found the following explanation about it:

The lyrics talk about the border between the real and the imaginary, and glass is a metaphor for the intersection between the two, revealing the transformations and transparency in human character.

Undoubtedly, the vocalist, who wrote the lyrics himself, was a very complex and profound person, whose interpretations of life are too complicated to understand.

I don't like reading biographies of people, most of them are distorted and tainted by the mainstream in order to sell.
But at the same time, after this article I felt the desire to read similar things, rather about such people, untainted and untouched by the mainstream (which has played a bad joke on them in their careers and their life).