Invention (musical composition)

first bars of J.S. Bach's 4th invention in D minor (BWV 775).

In music, an invention is a short composition (usually for a keyboard instrument) in two-part counterpoint. (Compositions in the same style as an invention but using three-part counterpoint are known as sinfonias. Some modern publishers call them "three-part inventions" to avoid confusion with symphonies.) Well-known examples are the fifteen inventions that make up the first half of Johann Sebastian Bach's Inventions and Sinfonias. Inventions are usually not performed in public, but serve as exercises for keyboard students, and as pedagogical exercises for composition students.