Johann Nikolaus Harnoncourt was an Austrian conductor, known for his historically informed performances. He specialized in music of the Baroque period, but later extended his repertoire to include Classical and early Romantic works. Among his best known recordings are those of Bach, whose 193 cantatas he recorded with Gustav Leonhardt.

Historically informed performance is an approach to the performance of classical music, which aims to be faithful to the approach, manner and style of the musical era in which a work was originally conceived.