invention

1. (music) A small, self-contained composition, particularly those in J.S. Bach’s Two- and Three-part Inventions.Examples: "I particularly like the inventions in C-minor."; "INVENTION. A term used by J. S. Bach, and probably by him only, for small pianoforte pieces — 15 in 2 parts and 15 in 3 parts — each developing a single idea, and in some measure answering to the Impromptu of a later day."countableuncountable

2. (archaic) The act of discovering or finding; the act of finding out; discovery.Examples: "That judicial method which serveth best for the invention of truth."archaiccountableuncountable