Matthieu, Georg David (1737-78). Medium: oil on panel. Date: 1774. Johann Christian Bach (1642-1703) son of Heinrich Bach, J.S. Bach's great uncle (according to the DDR); Johann Christoph Friedrich Bach (1732-1795), ninth son of J.S. Bach,the latter's first cousin once removed (according to the BRD); Provenance: Staatsbibliothek, Berlin, Germany. Photographic rights held by The Bridgeman Art Library.