Research on Johann Sebastian Bach’s life and works and on the extended Bach family of musicians belongs among the central tasks of the research institute. It hosts Bach scholars from all over the world and collaborates closely with other research institutions. The Bach Archive’s editorial projects include catalogues raisonnées of the music of the Bach family as well as the complete works of Johann Sebastian Bach and his two oldest sons, Wilhelm Friedemann and Carl Philipp Emanuel. Major long-term research projects address the history of the Leipzig St Thomas's cantorate; the Bach family and related musical documents in central-German communal, state, and church archives; and the Bach reception in Leipzig during the Mendelssohn-Schumann period.
The Bach Archive publishes books, critical editions, facsimiles, documents, and pamphlets for scholarly and general audiences.
The project "Expedition Bach" regards the systematic search for and scholarly evaluation of historical documents in federal, communal, and church archives in the historical territories of Saxony, Thuringia and Anhalt.
The contribution made by the musical dynasty of the Bachs to European music history is without parallel. The »Bach-Repertorium« project records the compositions of every member of the widely branched-out family of musicians.