the first musical description of the sonatas for obbligato harpsichord and violin bwv 1014–1019 appeared in . in the 1960s hans eppstein made a systematic analysis of all the sonatas for obbligato keyboard and melody instrument, including the six organ sonatas, bwv 525–530. he determined common features in their compositional forms; part of his aim was to investigate their possible origins as transcriptions of lost compositions for chamber ensemble. because of the complex history of bwv 1019, with its five movements and two previous versions, eppstein gives his analysis for the first five sonatas bwv 1014–1018, viewing the movements of the sixth sonata as hybrid forms. the movements of the three versions of bwv 1019 will be discussed separately in its own section below.