This 1984 release was the first in what could be very loosely said to belong to a trilogy of his 80's albums, the other two being Invisible Connections and Mask, both from the following year (1985).
He derived his inspiration for the collection from the life processes taking place on the Earth's surface. "I work like a bridge between nature and what comes out through my fingers" Vangelis told Jereme Jones in People.
"I write music primarily for myself, though it’s lovely, everybody goes out and buys the records. My new album Soil Festivities was made because I wanted to make music, not sell a million records. I don’t think it’s possible to guarantee commercial success for an album anyway, because nobody really knows what is commercial and what isn’t. Even if I went out of my way to make an album that was more accessible to the public, that would not guarantee its commercial success". 1
On the Japanese LP, Movement 5 ends a few minutes early. On the CD, there is a break in the middle of that movement. It was originally meant to be the end of Movement 5, after which Movement 6 would play to finish the album. Movement 6 ended up being "deleted" by combining it with Movement 5. This was all later corrected on a subsequent pressing.
Movement 4 is a minimalist elaboration of a single theme, which (likely by coincidence) is now widely known as the "Mockingjay call" from The Hunger Games films.