JOHANN SEBASTIAN BACH - Flute Sonata in B minor, BWV 1030 (1736-1737)

The trio sonata for two melody instruments and continuo arose in Italy in the 17th century and is considered one of the most important Baroque music genres. The basic idea behind trio sonatas is the rivalry between two upper voices of equal status, over a bass line that alternately supports those voices and actively participates in the musical argument. Bach created a modified version of the trio sonata which involves only two instruments: a melody instrument and an obbligato harpsichord. The latter is not merely a continuo instrument, but takes part in the performance of the obbligato treble voices or even contributes towards the entire three-part texture. Bach’s preferred melody instruments for partnering with the harpsichord include the violin, the viola da gamba, and the flute. 

In 1729, Bach took over Leipzig’s Collegium Musicum, a voluntary association consisting of professional musicians and university students that gave weekly concerts. Sonata in B Minor, BWV 1030 is believed to have been created for the Collegium concert series, and Bach’s acquaintance with Dresden’s flute maestro Pierre-Gabriel Buffardin (1689-1768) no doubt inspired him to write this work too. 

A posthumous copy of just the harpsichord part suggests that Bach began composing this sonata in a different key, that of G minor, around 1729-1731. He did not return to the piece until 1736/1737, at which time he prepared a fair copy in the key we know today – B minor. It is impossible for Bach’s originally intended solo instrument to be the flute because the two upper parts both go below the lowest note playable on the flutes from the Baroque period.

The opening movement Andante is unusually lengthy and complex, with a rich contrapuntal texture. Its initial theme recurs throughout, alternating with episodic passages, reflecting the signature ritornello structure of the Baroque concerto. Following it is the Largo e dolce, a beautifully harmonised “song without words”. It is presented in the form of a florid flute solo with a fully notated harpsichord accompaniment. The closing movement Presto is a combination of fugal textures and dance-like virtuosity. It has a unique structure; it contains two contrasting sections, an alla breve fugue, and a highly syncopated gigue-like second section. Surprisingly, that second section was created first. Bach, though, felt that the dance section “would be too lightweight as a counter-balance to the first movement”, and added the relatively weightier fugal part before it. To connect the two sections, Bach uses similar opening phrases which are both developed from the same five-note sequence: B–D–C#–G–F#.