"Spectral music (or spectralism) is a musical composition practice where compositional decisions are often informed by the analysis of sound spectra.
The term "spectral music" was coined by Hugues Dufourt in an article written in 1979 and first published two years later.[4] Dufourt, a trained philosopher as well as composer, was the author of several interesting flagship articles associated with this movement. It was initially associated with composers of the French Groupe de l'Itineraire including Dufourt, Gerard Grisey, Tristan Murail, and Michael Levinas, and the German Feedback group, principally Johannes Fritsch, Mesias Maiguashca, Peter Eotvos, Claude Vivier, and Clarence Barlow, as well as an independent form found in the work of Romanian composers Stefan Niculescu, Calin Ioachimescu, Horatiu Radulescu, and Iancu Dumitrescu.[5] Among recent composers building on the spectral idea are Joshua Fineberg, Magnus Lindberg, Ana-Maria Avram, Kaija Saariaho, Phillippe Leroux, Phillippe Hurel, and Julian Anderson.

(http://en.wikipedia.org/wiki/Spectral_music)"