Bach's Mass in B minor is a testament to a lifetime of work by the "King of Baroque"—but the masterpiece is not a typical Mass in scope or compositional history.
There's a lot that's unknown about Bach's Mass in B minor. It's a Catholic Mass written when Bach was in charge of the music for the principal Lutheran churches in Leipzig. While it has the traditional elements of a Mass in the conventional order, beginning with the Kyrie, it wasn't written that way. It's actually a collection of pieces composed over a 25-year period.
"What's different about it (from a typical mass) is that it's this tour-de-force," says Joe Miller, director of Westminster Symphonic Choir. "It's Bach showing everything that he learned his whole life."
When Bach wrote the Kyrie and Gloria in 1733 for Friedrich August II, Elector, or Prince, of Saxony, he'd already written the Sanctus for a Christmas Day service nearly 10 years earlier. He composed other parts of the Mass in 1748 and '49.
He died in 1750, and most likely never heard the Mass performed in its entirety. After his death, his son, Carl Philipp Emanuel Bach inherited the score and is known to have performed sections of it.
The whole Mass wasn't published until 1845; its first documented performance was in 1859 in Leipzig.
"I don't know that Bach ever really thought about the work being performed altogether, by one choir and one orchestra all the way through," says Miller. "The piece is always changing throughout."
Changing with different styles, instrumentation and vocal forces, from solos and duets to large choirs and double chorus. Miller points to the Credo as one example of the eclectic nature of the work:
"The piece is just with continuo and it's going to sound very old fashioned. And then immediately, when the text is introduced, patrem omnipotent and father omnipotent, then we become late Baroque splendor, with all sorts of trumpets, and the orchestration is just filled with life and exuberance"
While much is unknown about this work, what's certain is the powerful effect Bach's music still has, centuries later.
"I really think it is a language that speaks to something greater than ourselves," says Miller. "There is something about the tone of his voice. It's the rhetoric, how people relate to each other that puts us on a spiritual plane. And I also think it is the perfection of his harmony that just gives us that feeling that we're lifting off of this ground and going to something that is greater, that's beyond our human existence."