George Tzanetakis has uploaded a 30 minute presentation with an overview of music information retrieval (MIR). It contains a good introduction to Fourier analysis and STFT. (On the same site, there is also a 18 minute tutorial by Meinard Mueller on chroma features.)
Tzanetakis' presentation spawned a small discussion on the MUSIC-IR list about the origins of the term MIR. The earliest use seems to have been at Princeton in the 1960s for a software package used in research on Josquin by Michael Kassler et al. (See Kassler, 1966, "Toward musical information retrieval", Perspectives of new music, vol. 4 (1966), no. 2, p. 59-67).
Before ISMIR started in 2000, some of the work on MIR was published in Computer music journal and the International Computer Music Conference proceedings (a search for retrieval results in about 370 matching papers from 1975 onward).