As soon as the musical idea is there, as many keyboards as possible are connected to the control-desk, which in turn are directly connected to the applicable tracks of the multi-track machine. The idea now is to play as many keyboards as possible at the same time. That way, as broad a basis as possible develops, which only needs fine-tuning. After that it’s a question of adding things or leaving out things.
Can you guess the origin of a potential description of Zynthian?
The answer is here.
I read too:
While acknowledging that computers are “extremely helpful and amazing for a multitude of scientific areas”, he described them as “insufficient and slow” for the immediate and spontaneous creation and, in terms of communication, “the worst thing that has happened for the performing musician”.[59][16] He considered that contemporary civilization is living in a cultural “dark age” of “musical pollution”. He considered musical composing a science rather than an art, similar to Pythagoreanism.[6] He had a mystical viewpoint on music as “one of the greatest forces in the universe”,[59][129] that the “music exists before we exist”.[6] His experience of music is a kind of synaesthesia.[6][130]
Great Vangelis!!
Read this article (the reference [59]) to enjoy with more thoughts from the master:
Some pearls:
I spend a fair amount of time dealing with the electronic sources of sound. But please do not think computers! Computers are extremely helpful and amazing for a multitude of scientific areas, but for me, when it comes to creation, they are insufficient and slow. Therefore all of my efforts are to stay away from that beast.
“I realised that success and pure creativity are not very compatible,” he says. "The more successful you become, the more you become a product of something that generates money. Instead of being able to move forward freely and do what you really wish, you find yourself stuck and obliged to repeat yourself and your previous success.
“There are cases in which a film can stand on its own without music,” he says. "But if music is used, it’s better for it to touch the soul and create emotions that the rest of the film cannot do. Music should continue emotions where words finish.
And my favorite:
“Scientifically, believe it or not, music drives everything, because music equals universe and universe equals music.”
The music of Ainur? Could the Silmarillion be right?
I want to believe! 
Respect!
Coincidentally, this is my own conception of music composition, as it is of architecture. I consider that beauty stems from the fulfillment of apt generative relationships, into orderly arranged sonic phenomena, capable of signifying conjunctly more than their sonic content.
I see you point mate: the majestic Silmarillion’s onset is one of the most impassionate testimonies, for the hope for a self-conscious musical-mathematical framework of the whole universe.