Whereas Bach’s Violin Solos are preserved in a calligraphic autograph manuscript, the lack of a surviving autograph of the Cello Suites has long been a problem for performers and critical editors alike. The Cello Suites survive in four manuscript copies, which musicians consult in facsimile copies to guide their choices about discrepant articulations, ornaments, and notes. For some 150 years, most cellists and editors have taken the manuscript copied by the composer’s second wife, Anna Magdalena Bach (Source A), to be a kind of surrogate for the lost autograph, despite the fact that it contains numerous inconsistencies as well as slur markings that are ambiguous or apparently inaccurate. A recent edition by Andrew Talle (2018) has reevaluated the four sources, drawing particular attention to Sources C and D, which had long been disregarded due to their geographical and temporal distance from the composer. However, these manuscripts were copied by excellent professional scribes working from another (now lost) manuscript in the possession of Carl Philipp Emanuel Bach. They moreover preserve various details, clarifications, and embellishments that were added through the composer’s initiative, probably in the context of lessons or music making, and which are not preserved in Anna Magdalena Bach’s copy.