Bach's aspiration to compose a comprehensive body of "well-regulated church music" resulted in a rich collection of sacred cantatas, encompassing liturgical music for the entire church calendar. Around two hundred of these cantatas have survived, serving as a powerful expression of Bach's belief that "true music should be for the honor of God and the recreation of the soul." This sentiment, originally expressed in reference to the art of realizing a figured bass (where harmony is indicated by numbers), remains fitting for this particular collection. The selection of these magnificent works was influenced by considerations of number symbolism and other extra musical elements.
It may appear paradoxical that this profoundly cerebral music resonates so deeply with the emotions. However, as a performer, delving into the possible intentions behind Bach's musical choices brings us closer to the composer. Beyond the unmatched intricacy of Bach's contrapuntal writing, there exist additional layers of complexity, guided by his compositional decisions driven by various forms of symbolism, rhetoric, and numerology.
Since ancient times, the concept of simple proportions has been recognized as fundamental to the essence of musical sound. Medieval musicians, finding perfection in the Trinity, developed systems of musical notation based on this belief. Consequently, triple time came to be regarded as "tempus perfectum," while duple time was considered "imperfectum." Given that meter is an evident characteristic of any music, and triple time inherently evokes dance for us bipeds, this central principle of Christian doctrine had significant (perhaps unintentional) consequences for the character of sacred music.
In addition to references to the Trinity (3) and Christ's age (33), Bach also attached significance to numbers derived from his own name (BACH=14, 41=JSBACH, where A=1, B=2, etc.). While composition seemingly required Bach relatively little effort, one can speculate that his delight in these intricate numerical relationships provided "recreation" for his soul. Whether these complexities served as compositional inspiration, marks of devotion, or simply for his personal satisfaction, we can only conjecture.