Though not as famous as his sonatas and partitas for solo violin, Bach’s six sonatas for violin and obbligato harpsichord BWV 1014–1019 represented a major step forward in the genre. At the time Bach wrote them, Baroque composers would write out a violin or other solo instrument melody while only leaving traditional figured based chord markings for the accompanying continuo musician to improvise during the performance. Starting with BWV 1014 (if it was indeed composed first of the six), Bach wrote out precisely what he wanted to accompany the violin melody, and he asked the harpsichord to not only provide the bass line but a second melody line that promoted the instrument to be an equal to the violinist soloist.

—Ricky O’Bannon