It was the last electroacoustic piece written by Xenakis.With the invention of the dynamic stochastic synthesis and its application in this piece,at the same time Xenakis returned us to the roots of electroacoustic music.It is a study of the microstructure and an example of the musical creation of the micro properties of the sound.S709 is not reminding of the previous compositions of Xenakis, and it gives an impression of a very youth-like work (["":http://www.scribd.com/doc/28669193/Iannis-Xenakis-S-709-analysis]