Esa-Pekka Salonen has provided the following program note:

“Dichotomie was originally intended to become a short encore-type of piece. I wanted to write a surprise new work for Gloria Cheng for a concert dedicated to my music in Los Angeles in January 2000. I soon realized that the material I had invented had a tendency to grow into two very different kinds of music. It became obvious that this was going to be a longer piece in two movements, as the material seemed to have that sort of genetic code. I missed my deadline for the January concert, and kept working during the early months of the year 2000. I put the piece aside for the summer, and finally completed it in October.

“The first movement, Mécanisme, is indeed like a machine, but not a perfect one: more like one of the Tinguely sculptures (or mobiles – they really defy all attempts to categorize them), which are very active, extroverted, and expressive, but produce nothing concrete. I imagined a machine that could feel some sort of joie de vivre, and in that process, i.e., becoming human, would lose its cold precision. (Just think of Pinocchio, who loses the puppet’s perfect shape when facing moral dilemmas.)

“Organisme, the second movement, behaves very differently. Again, the music is busy on the surface, but breathes a lot slower and deeper. The music is completely continuous, all different sections grow into each other organically (as opposed to Mécanisme, where one thing just follows another). A metaphor I had in mind was indeed a tree, not a huge one, more like a slender willow, that moves gracefully in the wind but returns always to its original shape and position.”
— Esa-Pekka Salonen