Name given by J. S. Bach to 15 of his shorter kbd. comps. in 2 parts or ‘voices’, incl. in his Klavierbüchlein, 1720. They are highly contrapuntal, being largely in the nature of imitation. Each works out some short melodic motif. Bach also left another 15 comps. in the same style, now known as his ‘3‐part Inventions’, to which he gave the title ‘Symphonies’. The term was used before Bach's day for short vocal or instrumental pieces by Dowland, Janequin, and Negri, among others. It has occasionally been revived in the 20th cent., e.g. by Blacher and Berg.