The demanding nature of the elaborate and physically challenging music which Bach writes for these singers in the Missa would have been out of place at the Thomaskirche and a simple comparison between this and the choral writing found in the passions, the cantatas and the Magnificat, all of which were written for the Thomaskirche, substantiates this. This music was written for a different audience, and a different type of musician from those in Leipzig. It would have fitted very well with the house-style of Dresden, and yet is more elaborate and skilful than those of the Italian contemporaries which were popular with the Court at the time. This music was written to impress. It is a fusion of the current Galant style with the contrapuntal complexity and integrity of Bach’s own style and would have met favourably with the expectations and requirements of the Dresden Court. We do not know if such a performance ever took place, and, as there is no evidence of one having occurred, it seems unlikely that the Elector favoured Bach with a performance. In any event, the hoped-for appointment to Dresden was not forthcoming, and Bach returned eventually to Leipzig to resume the battle with his employers. 

Following the Dresden experience, and the presentation of the Missa, we have to wait for another twelve years before any further trace of the work surfaces. The trigger for its reappearance appears to have been a special service at Christmas time in 1745. Following the end of the second Silesian war, Prussian troops were stationed at Leipzig, and a service of thanksgiving for the restoration of peace to Leipzig was held at the university church. For this occasion, as senior town musician, Bach was responsible for the music, and he had at his disposal both of his best choirs – those of the Thomaskirche and of the Nikolaikirche, and all of his municipal instrumentalists. It seems that Bach combined these forces and thus created the opportunity for one large scale performance. A mass being inappropriate, Bach converted three movements of the original 1733 Dresden Gloria into a Cantata (BWV 191) and titled it Gloria in Excelsis Deo. Furthermore, he revised the six part Sanctus from Christmas 1724, and so it appears that four movements of what was eventually to become the Mass in B Minor that we know today were performed on that occasion, and directed by Bach, albeit under a different guise. This may have been the time at which the momentous decision was taken by Bach to complete the mass and create the setting we know today. 

We do not know the real reason why Bach devoted so much time in the final half-decade of his life to revising, re-writing, parodying and compiling a collection of movements written across his entire adult life into a single massive work which so precisely matches the requirements of the Ordinary of the Roman Catholic High Mass, when he was so entrenched in German Lutheran Protestant church music. There is some speculation amongst Bach scholars that the complete work was destined to be performed under Bach’s direction in 1751, at the annual gathering in Vienna of a group of wealthy men; a kind of musical brotherhood, who collectively celebrated a High Mass at St Stephen’s Cathedral in Vienna every year on St Cecilia’s Day (November 22^nd), and at which prestigious and virtuosic musicians and composers from across central Europe were invited to participate. This brotherhood included wealthy and prolific patrons of the arts such as members of the families of Esterhazy and Razumovsky. This particular High Mass was a grand and lengthy celebration of music and Catholicism, and the completed Mass in B Minor would have fitted very well into this event. Whether Bach had actually received an invitation to provide music for this occasion we do not know; however, his death in 1750 prevented it from becoming a reality in any case.

The final decade of his life was also dominated by the composition and publication of Die Kunst der Fuge (BWV 1080, The Art of Fugue). There is, however, an alternative theory as to why Bach was prompted to finish the work in the late 1740s, in which the city of Dresden returns again to the story of this opus. It has been suggested that Bach saw a potential opportunity for a performance (away from the Leipzig Lutheran stronghold) at an important new church which was not yet complete. In 1739 the corner stone had been laid in Dresden for a new Catholic church which was to be called the Hofkirche (or Court Church). Work on this building, known today as Dresden Cathedral but at the time destined to be the elaborate private chapel of the Royal Court of Saxony, was well advanced. An oil painting from 1749 shows the building to be almost complete with only the bell tower still encased in scaffolding.