Clavier Suites
Bach's clavier suites show the influence of French and Italian as well as of German models. There are three sets of six suites each: the "French" and "English" Suites, composed at Cöthen, and the six Partitas published separately between 1726 and 1730 and then collected in 1731 as Part I of the "Clavier Übang."The designations "French" and "English" for the suites are not Bach's own, and have no descriptive significance. The suites in both sets consist of the standard four dance movements (allemande, courante, sarabande, gigue) with additional short movements (one of various types: minute, bourrée, gavotte, passepied, polonaise, etc.) between the sarabande and gigue; each of the "English" Suites and Partitas opens with a prelude. Some of these preludes illustrate particularly well the skill with which Bach transferred Italian ensemble forms to the keyboard: the prelude to the third suite, for example, is a concerto Allegro movement with alternating tutti and ritornellos (like a concerto grosso). The preludes to the first three Partitas are modeled after the Inventions, that of the fourth is like a French overture, and the last two borrow their style from the toccata. The dances in the "English" suites are based on French models, and include several examples of the double or ornamented repetition of a movement. In the "French" suites, the second movement is more often an Italian corrente than a French courante.
The dance movements are generally in binary form, either symmetrical (both sections of equal length) or asymmetrical (the second section expanded in a manner foreshadowing the sonata form).
Orchestral Suites
The four "Ouvertures" or orchestral suites (BWV 1066-1069) are likewise masterly example of this favorite type of Baroque composition, and contain some of Bach's most exuberant and attractive music. The third and fourth suites, which have trumpets and drums added to the strings and winds, were undoubtedly intended for performance out-of-doors. The piece popularly known as "Air for the G String" is an arrangement of the slow movement of the third suite.(See also The Instrumental Suite)