Anyone who listens initially to each piece individually of this collection of the shorter works of Johann Sebastian Bach and is consequently spurred on to practise and play them, preferably piece by piece, can almost call himself a pupil of the great Bach. For in this collection, Bach presents himself pre-eminently as one of the most important pedagogues of his time for harpsichordists, pianists and organists as well as for young composers. Bach thought that learning to play an instrument, teaching another person to play that instrument and learning to compose were closely associated with each other. Only in this way the passing on of knowledge and experience was guaranteed. Anyone having lessons from Bach was also looked upon as a member of the family. Practically it was not always possible for Bach to put up his pupils in his home (his own large brood of children prevented this), but they did come to his home everyday to receive their daily tuition. He shared the same opinion with his French colleague and contempory François Couperin which was that there is no better school than the daily one. Bach’s teaching method began with the correct positioning of the hand and fingers. Pupils had to have a complete and effortless control of weight, pressure, speed and relaxation before progressing to the following stage, that of playing the first pieces of music. In all his tuition, he emphasized the value of following good examples. Bach often played for his pupils to let them see, hear and feel how it should be done. The pupil had to acquire for himself all the necessary technique and knowledge step by step, applying understanding and perception. The fifteen two-part inventions and the fifteen three-part sinfonias are also compiled in this way, as well as the complete Klavierbüchlein of which they form a part. These were written down for his oldest son, Wilhelm Friedemann (and partly in conjunction with him) during the last years in Köthen. As stated by Bach in a brief propagandist text, the aim of the inventions and sinfonias (nowadays generally called two- and three-part inventions) is, on the one hand to teach clavier enthousiasts, especially those keen in mastering two-part playing and eventually in learning three-part clavier works after sufficient progress (including development a good singing or cantabile tone) and on the other hand to give these same pupils a chance to acquire a sound taste in composition. Composition is principally about the right inventio or ingenuity: a joining together of knowledge, combinative capacity (the compositio) imaginative powers and fantasy. Inspiration alone is not enough. It is certain that up until the beginning of the nineteenth century composition was primarily a science and demanded, like all sciences, a great deal of research preferably based on good examples. Just as Bach learned the profession through copying the music of his great Italian and German predecessors and older contemporaries, in the same way the inventions and sinfonias, many short studies from the clavier books for Wilhelm Friedemann and Anna Magdalena Bach, the Klavierübungen, The Well-Tempered Klavier and The Art of the Fugue were intended for his numerous pupils. They were to serve as a replenishing source, a source so rich, it was comparable to none in our musical history. Through playing all these compositions one by one, analyzing, transcribing, imitating and finally using them as a base for one’s own work, the whole domain of the compositio and the inventio is revealed to all; from simple to complex, with and without modulation, in abstract canons and fugues, but also in elegant dances and ornate arias. Time after time we are amazed by Bach’s melodic and harmonic ingenuity and the eloquence of each individual voice. Even the simplest turn is testament to his generous musical mind. The basis of the inventions, sinfonias and preludes was formed through learning to trust the laws of nature in counterpoint. Those who keep to the rules of the game with regard to phrase construction, rhythmic variation and harmonic modulations cannot go wrong. The two- and three- parts imitate each other, sometimes only at the beginning, sometimes for a few bars, sometimes – as in a canon –exactly and completely the same. In short linking passages, the reigns can be slackened, allowing scope for sequences (the same figure is repeated at different pitches) and for modulation (changing from one key to another). The main theme and the counter subject must each have their own character and at the same time connect perfectly with each other. This should happen simultaneously (when they sound together in two parts) as well as following each other, when the counter subject serves as an extension of the main theme. Bach has only used a ‘free’ third voice against strict two-part upper harmonies in a single three-part sinfonia. His work is considerably less impeded in many of the short preludia, for example the group of six from the clavier booklet for Wilhelm Friedemann , the six from the Johann Peter Kellner collection and the six preludes à l’usage des Commerçants (for beginner’s use - as specified in a posthumous edition around 1780). It is not totally certain in every case how far we can attribute all these preludes to Bach. This too was a part of his mastery in teaching: he often held on tightly to the writing hands of his pupils. So it is not inconceivable that the third and sixth prelude from the first set (BWV 925 and 927) could have been composed by Wilhelm Friedemann, albeit under the supervision of his father. Likewise a pupil could have written the first four preludes of the second set (BWV 939-942), wheras BWV 943 and BWV 999 are definitely from Bach himself. The prelude BWV 999 was originally known as a Preludium for lute, but it became a real hit as an ‘etude’ for piano at the beginning of the nineteenth century due to Czerny’s intervention. The third set (BWV 933-938) originates completely and with great certainty from the hand of Bach himself. Although the inventions, sinfonias and preludes must be considered as the ‘strict’ compositions, which above all deal with contrapuntal, mainly imitating, movement between the parts, Bach repeatedly indicates where ornaments can be included. Furthermore the playing of ornaments is also subject to rules. Bach indicates this precisely. That does not rule out that he leaves it to the good taste of the performer to embellish the notes according to his own discretion. Leo Samama, 1999