When it comes to Johann Sebastian Bach, it seems that enthusiasts might know all about the music but have had little chance to understand the man. The innovative musical genius behind some of the world's most renowned compositions has been practically a cipher. The music he's left has spoken for him.

In Bach: Music in the Castle of Heaven, the classical conductor and first-time biographer John Eliot Gardiner analyzes that music, the era in which it was composed, and Bach’s own writings to bring his subject to light. This book swells with information. Readers are immersed in the Germany into which Bach was born, as his country recovered from the Thirty Years’ War and teetered on the brink of the Enlightenment. It is brimming with explanations, history, and footnotes about the religious musical tradition in which Bach was steeped.

In a typical paragraph, Gardiner connects Bach's music to the tradition of Galileo, Copernicus, and Newton. This reaching works, as he's able to explain the way in which “a capacity for dealing with abstractions and for eliciting from them clear-cut demonstrative trains of reasoning was to provide the springboard for his imaginative thought as a composer.”

Gardiner is at his best in the chapter “Cantatas and Coffee,” in which he illuminates, through exhaustive research and commentary, the exact motivations for Bach's compositional decisions. He paints a picture of church services in Germany and, in colorful detail, describes the sermon's role as social occasion, with ladies in their ostentatiously wide skirts arriving late on purpose to draw the attention of the crowd. Meanwhile, other churchgoers were doing snuff, reading the paper, and throwing paper darts. There may even have been dogs running up and down the aisles. “One might think that the music stood little chance of being heard,” he writes, almost superfluously.

Bach, a stubborn man who was “almost constantly at odds with someone or something” would not settle for being mere background music for these church gatherings run amok, and developed “shock techniques” to jump out at his audience at the precise moments their interest might have been drawn elsewhere. A “ferociously demanding trumpet obbligato set against the rest of the orchestra” is timed to capture the attention of latecomers. Soon after, he fashions an “abrupt ending” to a piece that is “calculated to give a sharp jolt to any congregation expecting, but not getting, the traditional chorale to round things off and to bring them comfortably back to earth after a stern homiletic reproof.”

In these pages especially, Gardiner shines. The image of the bustling church crowd is entertaining enough on its own, and the image of Bach, “an irascible man, passionate in defence of his craft and bristling at any perceived threat to his right to practice it unobstructed,” administering a sonic reprimand, makes the scene pop. But what makes it matter, and what makes it insightful, is the way that Gardiner yields his musical insight (and formidable vocabulary) to make us understand the context for art of such historical importance.

And if none of that grabs your attention, skip straight to the chapter “The Incorrigible Cantor,” in which there's a scene where a bassoonist and his posse, “well oiled after attending a christening party,” try to attack Bach in the street, only to have him draw his rapier on them.

To purchase original Biographile illustrations by Nathan Gelgud click here.