Six Sonatas for Violin and Harpsichord, BWV 1014–1019

The six sonatas for violin and obbligato harpsichord BWV 1014–1019 by Johann Sebastian Bach are works in trio sonata form, with the two upper parts in the harpsichord and violin over a bass line supplied by the harpsichord and an optional viola da gamba. Unlike baroque sonatas for solo instrument and continuo, where the realisation of the figured bass was left to the discretion of the performer, the keyboard part in the sonatas was almost entirely specified by Bach. They were probably mostly composed during Bach's final years in Cöthen between 1720 and 1723, before he moved to Leipzig. The extant sources for the collection span the whole of Bach's period in Leipzig, during which time he continued to make changes to the score.

Bach's sonatas for violin and obbligato harpsichord were composed in trio sonata form, i.e. three independent parts consisting of two equally matched upper voices above a bass line. Instead of playing the role of a continuo instrument, filling in the harmonies of a figured bass, the harpsichord took one of the upper melodic lines on equal terms with the violin, whilst also providing the bass line (which could be reinforced if desired by the addition of a viola da gamba).

In the totality of Bach's musical output, the instrumental sonatas written in trio sonata form are small in number. Apart from the BWV 1014–1019, there are the six organ sonatas, BWV 525–530, the three sonatas for viola da gamba and harpsichord, BWV 1027–1029, and the three sonatas for flute and harpsichord, BWV 1030, BWV 1031 and BWV 1032. In each case the trio sonata texture derives from the compositional form and not the particular combination of instruments, which was partly a function of the musicians at Bach's disposal. This is well illustrated by the first movement of the organ sonata BWV 528 which originated as the sinfonia starting the second part of the cantata, BWV 72, with oboe d'amore and viola da gamba as solo instruments; and likewise by the trio sonata for two flutes and continuo BWV 1039 and its alternative version for viola da gamba and obbligato harpsichord, BWV 1027.

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