Counterpoint and fugue are often the first things that the music of J. S. Bach calls to mind. Yet while it is extremely important to recognise Bach's remarkable achievements in the field of counterpoint, it is perhaps a mistake to give these first priority in a broader analysis of his work. Counterpoint remained the primary compositional procedure of Bach's age (whether studied or practised in its strictest form or in the shorthand of figured bass) and constitutes the basic fabric of all compositions, however chordal or ‘harmonic’ they may appear. Therefore counterpoint and fugue itself were techniques rather than forms: the means of passing from one note or conglomeration of notes to the next, the means of controlling and displaying the principal thematic material, the inventio. Certainly many works of Bach's may be described as fugues, but the relevance of fugal procedure to the structure as a whole is often only local. For instance the Kyrie of the Mass in B Minor is a large-scale ritornello movement (see p. 69) as well as a fugue, so an analysis purely in terms of fugal process would necessarily be superficial.

Nevertheless, counterpoint is the next focal point in this study, standing as it does between the larger formal principles which influence the structure of individual movements, and the motivic detail of the instrumental and vocal lines. Many elements of Bach's compositional style will emerge that are already familiar: the sense of proportion, economical use of the material, and the subtle frustration of expectation.