In the autograph of his Inventions and Sinfonias, J.S. Bach set out the aim of these pieces, formulating a dual purpose: the keyboard player should, on the one hand, practise contrapuntual playing in two or three onligatory voices and develop a 'cantabile' style; at the same time he should also be given an introduction to the study of composition, and learn how a piece can be developed from an invented theme (Inventio) by means of imitative techniques.