Christoph Wolff, the eminent scholar of Bach in recent years, has written the following regarding the sonatas for violin:

"The violin sonatas form a self-contained group of six works and in this respect resemble a series of other instrumental compositions by Bach; for instance the six Brandenburg concertos, the six Sonatas and Partitas for Solo Violin, the six Partitas of the first part of the Clavierubung (keyboard exercise) or the six Schubler chorales.  However, the compactness of the individual groups as such does not consist of, for example, a cyclic arrangement in the sense of specific sequence of performance.  It is based rather on the principle, which Bach applied with systematic precision, of exhausting the many possibilities of a definite type of work and exemplifying it as an "opus" by half a dozen compositions. The groups of works are secured by various characteristics which give them inner cohesion.  Going beyond the unvarying sound medium, these include in the violin sonatas, above all, the continuous obligato treatment of the harpsichord, the sonata design and the tonal balance (three works in the major key and three in the minor key)."

Bach’s violin sonatas owe a great deal to the genre of the trio sonata and its movement structure.  With regard to the external formal design, they accord particularly with the four-movement type of sonata da chiesa, with the movement sequence slow-fast-slow-fast. Characteristic of the sonata da chiesa is its contrapuntal development and the lack of dance like movements, the essential elements of the sonata da camera.

One of the most important features of the music of the Baroque is the association of keys to certain moods and feelings.  Each key had a type of color.  Johann Matheson discusses these key relationships as they relate specifically to Bach’s violin sonatas in his work, Das Neu-Eroffnete Orchestre.  He says of the f-minor sonata:

 "F-minor seems to be calm and gentle, but it is also profound and weighty, having something of despair about it, able to represent the most heartfelt concern, and it is flexible beyond measure."

Like all works of Bach he introduces nothing new to the creation of the form but rather a perfection of all the preexisting forms and procedures known to Bach during his lifetime. This perfection was carried out in cycles which is done, as Wolff states, in order to create cohesion and complete development in each genre.

We have in the violin sonatas of Bach some of the richest and exceptional examples of composition for the instrument in which the colors and characters of the violin and harpsichord are exposed.