Bach's Major Vocal Works:Music, Drama, LiturgyMarkus RatheyYale University Press, 2016When Johann Sebastian Bach was composing his stunning body of liturgical vocal works, during his six years as a church musician in Leipzig leading up to his taking control of the Collegium Musicum in 1729 and then in the following years at the height of his fame and mastery, the works were immeasurably aided by context. As Markus Rathey reminds his readers in his small but invaluable new book Bach's Major Vocal Works, most modern audiences hear those works in radically different settings – and mindsets – from those for which they were originally designed:

Things have changed since the 1720s. While we still regard Bach as a composer of sacred music, his major pieces have moved from the church to the concert hall, or at least from the liturgy to extra-liturgical performances in churches that serve as concert spaces. However, when listening to Bach's music, it is important to keep in mind that his most celebrated works, his passions, the Christmas Oratorio, the Magnificat, and the smaller oratorios for Easter and Ascension, were composed for use in worship services.

Rathey's book works against that radical shift in context by acting as a basic guide and overview to such major works as the St John Passion, the Christmas Oratorio, and the St Matthew Passion. Rathey is an associate professor of music history at the Yale School of Music, the Yale Institute of Sacred Music, the Yale Department of Music, and the Yale Divinity School – an incredibly impressive cv that at a minimum guarantees two things: he knows his subject, and more importantly, he knows how to teach his subject.His chapters are modular, self-contained things; the book is not so much a running commentary on Bach's vocal works as it is a series of wonderfully insightful lectures on each work in turn, pointing out for readers the highlights of the history, performance, and musicology. The aim here is to introduce, and thus the target audience is newcomers to glory of Bach's singing pieces. But even readers already familiar with these pieces will be consistently fascinated by Rathey's thoughts on them; he frequently indulges in the kinds of elaborating asides that would make anybody envy his students, as when he's discussing a certain passage in the great Easter Oratorio:

Reasoning, 'wisdom of the world,' is cold. Bach expresses this coldness with a shockingly harsh and chilling chord at the beginning of the first recitative. We have just left the lavish and exuberant sounds of the first vocal movement, when the basso continuo plays a diminished seventh chord, on top of which the alto sings her criticism of the cold male disposition (or mind). The soprano aria “Seele, deine Spezereien” (Soul, your spices) provides a counter model, a highly emotional aria that describes how the soul should not be embalmed with myrrh, but it should rather be crowned with laurel. The aria is about ornamentation, embellishment, and eventually about beauty: the beauty of the soul that opens itself for Christ. Beauty is not rational, not even functional. It transcends function.

Bach's Major Vocal Works is an intentionally brief affair, meant to be welcoming rather than intimidating. The perfect accompaniment to having each chapter open in front of you would be having the relevant music pouring out of your stereo speakers. And, as Rathey rightly stresses, the next step is to go to your local church or concert hall and surrender yourself.