The Bach archive in the German city of Leipzig has released a photograph of a facsimile of a previously unknown composition by Johann Sebastian Bach. The gem, which was unearthed in the archives of the Herzogin Anna Amalia library in Weimar, dates back to 1713. The foundation of the Bach archive announced on Tuesday that the composition was scored as an aria to be sung on the occasion of Duke Wilhelm Ernst von Sachsen-Weimar's 52nd birthday.