This article highlights the use of computer technology in the creation of spectral music. It discusses the emergence of computer music in the 1950's, the relationship between composers and scientists and how emerging research, development and experiments in physical modelling, in particular the work of IRCAM, gave sound synthesis some of its first proofs of musical respectability. The article also presents four case studies of spectral music composers who have worked at IRCAM and have realised pieces which share, despite their aesthetic differences, a common sensitivity toward the notion of models. Joshua Fineberg - Empreintes, Tristan Murail - l'Esprit des dunes, Philippe Hurel - Lecon de choses and Claudy Malherbe - Locus. These composers have all used the computer and have reflected on the innovative aspects of using computer technology.