For musicians and musicologists, 'timbre' is an element of a musical work which is responsible for the organisation of its progress; for psycho-acousticians, 'timbre' refers to acoustic events which often have only a phonological aspects, as well as acoustic events which, apart from phonological characteristics, have syntactic and semantic features. The article presents the state of research into timbre both from the acoustic point of view, and from the point of view of its functioning within music. It aims to sketch a general description of the research, its subjects and the methods it employs, up to and including the final decade of the twentieth century. Among the many detailed conclusions from the research, there are also more general observations which deserve attention. These include the fact that the properties of timbre revealed during the perception of music are in part a function of the acoustic properties of the perceived objects, and in part a function of perceptual processes. An important aspect of these deliberations is also the claim that appropriately shaped timbre causes different perceptual effects, which contribute towards producing concrete auditory representations of the perceived material.