Most listeners will recognize the Bach Gloria in excelsis Deo, BWV 191 from the very first bar: it is based entirely on the “Gloria” from the B minor Mass, BWV 232. This composition has posed all sorts of questions for scholars and biographers of Bach, as it is not a cantata in the usual sense of the word, and it is unlikely, with its Latin text, that it was performed for a church service in the Thomaskirche. The most likely occasion for its first performance was a special service of thanksgiving held in the University church in Leipzig on Christmas Day 1745 to celebrate the Peace of Dresden. The second Silesian war had just come to an end, the only time in his life that Bach had first hand experience of the horrors and suffering of war as Prussian troops occupied Leipzig and devastated its surroundings in the autumn of 1745. Thus the passage "et in terra pax" would have acquired a particular concrete meaning.
Bach scholar Klaus Hoffman posits: “It would thus seem possible that this composition might have been the ceremonial music for this peace celebration. Everything fits: the choice of text with its heavenly message of peace, the Latin language (which was in common use in the University Church), and also a note by Bach in the score that the second and third movements should be performed ‘post Orationem’, ‘after the oration’. The forthcoming peace treaty seems not to have become public knowledge in Leipzig until 22nd December at the earliest. Bach’s music for the festivities must therefore have been produced in great haste, and this time pressure would also explain his recourse to a work that already existed, and his pragmatic choice to make as few alterations as possible.”
The opening “Gloria” remains virtually unchanged. Bach retains the five-part choir (only once used elsewhere in the cantatas), the instrumentation and the text. The following two movements were adapted and set with new texts. The soprano/tenor duet with flute, originally the “Domine Deus,” is now a simple tribute of glory to the Father the Son and the Holy Ghost. This constraint, plus the requirement to change the ending so as to finish in the tonic key, led Bach to significantly shorten the model from the Mass by leaving out the B section.
The concluding doxology, “Sicut erat in principio” (originally “Cum sancto”), takes off with a tremendous burst of action. The words are combined with a new, signal-like motif that effectively opens the work and is subsequently heard several times in two or three parts, an octave apart. Our cantata concludes as the triumphant first trumpet rings out a message of peace for humankind.
© Ryan Turner