Motetta "Merk auf, mein Herz, und sieh dorthin" => original (Bach Digital) Harverd University Library
Composer => "Sign. Bach Cugino del Giov: Seb: Bach" (Mr. Bach who is a cousin of J. Sebastian Bach)
Candidate persons => Johann Bernhard Bach(1676-1749) --- Erfurt family, Eisenach
Johann Ernst Bach(1722-1777) --- Erfurt family, Eisenach
Johann Nikolaus Bach(1669-1753) --- Arnstadt family, Jena
Johann Christoph Bach(1642-1703) --- Arnstadt family, Eisenach
bar1-22 : A part, Coro 1 only
bar23-50 : B part, Coro 2 only
bar51-69 : C part, from Choral "Vom Himmel hoch, da komm ich her"
bar70-175 : D part
bar176-203 : E part
bar204-291 : F part
bar292-326 : G part, Choral "Vom Himmel hoch, da komm ich her"