A surviving manuscript of the
St Luke Passion from about 1730 is partly in Bach's hand, though scholars believe that the music is certainly not his own. The music was later thought to have been composed by
Johann Melchior Molter, but that was proven false because if Molter composed the music, then the manuscript would date to later than 1730. Presumably Bach performed it, or intended to perform it, in Leipzig. C. P. E. Bach and
Agricola may have mistaken it for a work of Bach's and thus included it in their census. Of course, given his delight in exhaustive cycles, Bach should have composed a
St Luke Passion. Apparently J. S. Bach took the anonymous
St Luke Passion and arranged it for four voices, chorus, orchestra, and continuo to meet an urgent deadline for
Good Friday in 1730. ==Authenticity==