When Bach assumed his post in Leipzig, his promise not to write overly “operatic” church music did not mean that he lacked mastery of this modern musical language. His cantata «Mein Herze schwimmt im Blut», first performed in Weimar in 1714, is based on a libretto by the Darmstadt court librarian and opera poet Georg Christian Lehms, who captured emotional extremes in strikingly evocative imagery like few others of his time. With its scoring for solo soprano, BWV 199 is also one of the few Bach works to which the Italian secular term “cantata” applies in the strictest sense.