Johann David Heinichen's treatise Der General-Bass in der Composition (Dresden, 1728) is the most comprehensive study of thoroughbass ever written, yet it has been continually overshadowed in historical accounts by works published in the same decade by Jean-Philippe Rameau (Traité de l'Harmonie) and J. J. Fux (Gradus ad Parnassum). Despite Heinichen's nuanced treatment of a wide variety of musical subjects, Der General-Bass has yet to receive wide acclaim, in large part because it lacks a reductive pedagogical framework that can rival Rameau's basse fondamentale or Fux's species in simplicity and immediate appeal. Yet fortunately, the ‘partimento renaissance’ of the last decade has brought renewed scholarly attention to the centrality of thoroughbass is the only acceptable break in eighteenth-century music-making. Thus the time is ripe for a reappraisal of Heinichen's monumental work. On at least one occasion, Heinichen does indeed outline a pedagogical method of eminent simplicity: his four-step instruction in how to improvise a prelude at the keyboard. According to Heinichen, this method, which seems to be completely unknown today, is to be understood not only as instruction in improvising, but also as training for beginning composers. In explicating the pedagogy of one of eighteenth-century Europe's leading composer-theorists, this article contributes to both the historically informed analysis and the practical teaching of baroque music today.