Use of Forms

When I first read The Use of Forms article, I was somewhat confused. The jargon used by the author was dense, and it wasn't until the example of audio mixing that I began to understand the meaning of détournement. The whole idea of utilizing a "history of sound," or any other art form for that matter, is very intriguing to me. For example, by treating previous works of art as elements to be used for future creation, old songs that have become stagnant over the years can be revitalized and incorporated into new works of art. I don't think that integrating previous works of art into a new creation is "stealing," because all art forms are inspired by something else anyway.
I have a logistical question about this art form. If détourage is seen as the most recent genre of art, then does that mean that no new elements will be introduced into the "history of sound/images/video/etc.?" Of course remixed elements can be recombined into other works of art, but are we destined not to have any new basic building blocks with which to make art?
I did a little bit of research on Ken Ishii, who is one of Japan’s most famous techno musicians. He has recorded sixteen remixed albums within the past fifteen years, and one of his most notable accomplishments was composing the music for the opening ceremonies of the 1998 Winter Olympics in Nagano, Japan.