The objective of this study is to identify the main conceptual dimensions of tonal musical style in order to provide a theoretical understanding of the phenomenon which could constitute the basis for a scientic taxonomy of styles. Music style is a substantial quality of the musical material that can be readily recognized as belonging to individual composers or associated with their epoch. I was initially attracted to the topic through the knowledge of the successes of literary stylometry, in the expectation that similar accomplishments could have been achieved in the realm of music. I was surprised to nd that, although musical style is a notion whose meaning seems familiar to everybody, it is conceptually elusive and had not been the object of a scientic enquiry. Therefore, music style became the core of the project. The most outstanding characteristics of this study are its quantitative nature and the eort to avoid subjectivity, considering only observable, measurable features. The work has been carried out exclusively on the basis of numerical continuous variables resulting from actual measurements eected by software. In order to accomplish this goal, I was concerned exclusively with those aspects of musical style that are detectable in notation. The traditional paradigm of problems of this sort consists of taking a large number of measurements on representative samples expressing the phenomenon under study, and then submitting them to statistical analyses that could be expected to lead to the determination of its main conceptual dimensions. Consequently, the methods comprised several stages. The project began by creating a database of music scores that tried to represent adequately the stylistic spectrum of the period of common practice. Since most of the stylistic elements of interest are key-dependent, the next and crucial step was to determine the key at every point in the score. This was accomplished following the method developed during my own previous research, whose result is a tonal map of the musical score.