Schoenberg's 'timbre' piece

In his book on harmony Schoenberg remarks that " it must also be possible to make progressions out of tone colours....progressions whose relations with one another work with a kind of logic entirely equivalent to that logic which satisfies us in the melody of pitches."
This is often linked to the 3rd of his orchestral pieces:

(with some analytical commentary from F. Nicolas). Using canonic devices probably influences Ligeti in pieces such as Atmosphere:

(Again with some illustrations about the constructions).