Offered here for the first time in English, The Aesthetic of Johann Sebastian Bach (L'Esthétique de Jean-Sébastien Bach), by the celebrated scholar and organist André Pirro, was originally published in 1907. Considered a masterpiece by many, it supports a uniquely engaging analysis that has informed and moved readers for more than a century. This translation introduces Pirro's work to a new audience of those who wish to have a greater understanding of the expressive import of Bach's music. Performers, in particular, will find it a valuable touchstone for instilling every figure and phrase they play with an ever-deepening range of feeling. Focusing first on the meanings of the motifs and other devices that Bach uses to depict the emotions, actions, and atmospheres of particular vocal settings, Pirro then carefully examines how Bach makes use of these devices in his instrumental accompaniments, orchestrations, pieces without a text, and even choices of compositional forms. The study concludes with an examination of the influence Bach's predecessors and contemporaries had on his work and offers Bach as an exemplar of a uniquely German spirit through the religious devotion and attitudes toward love, nature, and humor manifested his music.