Gregory Butler focuses on Bach's Concerto for Harpsichord and Strings in E Major (BWV 1053) as a pastiche created by a process of assemblage of three earlier heterogeneous movements. Pieter Dirksen delves into the source history of the Concerto for Harpsichord and Strings in F Minor (BWV 1056) and concludes it represents a transcription of an earlier violin concerto in G minor. David Schulenberg investigates the generic ambiguity of the concerto in the early eighteenth century and how it diverged from the sonata to become a distinct genre. Completing the volume is Christoph Wolff's examination of the ""Siciliano"" as a slow movement in Bach's concertos and its implications for the source history of his Concerto for Harpsichord and Strings in E Major (BWV 1053).