Bach 's Inventions is a collection of 15 Two-Part and 15 Three-Part pieces. Originally composed as pedagogical exercises for his students, their contrapuntal composition still works brilliantly as an introduction and practice in counterpoint. Bach  wrote the Inventions  as a way for his students to practise playing in two parts, then, after some progress, in three parts; with an end goal of becoming more accomplished at composition. The two groups of pieces are arranged in order of as...