I have the impression that Iannis Xenakis is a solemn thinker and composer. There is a tension in his music that seems to be contained in a particular space. To be corny his music can be used for a horror film, but the compositions can give one image in one's head without the visuals being projected on a screen. It shouldn't be a surprise, but one of the pieces on this album "Orient-Occident" (1960) is a soundtrack to a film. It's a documentary about a visit to a museum and comparing artifacts from different cultures. The film may be wonderful, but the music I think is even better.
Xenakis' work is a sonic/aural landscape. Sophistication as an artform. There is nothing wasted, it seems all sounds have a proper place. The first piece on side one is "Concret PH" (1958) commissioned by the huge company, Philips, it took place at the Brussels World Fair. There were 400 speakers in the Le Corbusier's pavilion. I have only two speakers, but have the volume up loud. Xenakis thought very much of space and how to fill that area with music. In a sense, one can imagine that he did sound poetry for that location.
"Bohor" (1962) is the longest work on this album. Almost 22-mintues of tension being built. It's similar to "Concret PH" in that there are ambient touches, but in no is this a relaxing listening experience. It's very urban with what sounds like crowd noises but more ghost-like than anything else. The music on this album serves as a magnet where I can't help but be drawn into its world.