Brandenburg Concerto No. 6 BWV 1051
Johann Sebastian Bach
The Sixth Brandenburg Concerto limits its palette to the lower strings, including instruments from the viol family that have since fallen out of fashion. With the violins absent, the two top lines go to instruments labeled viola da braccio, or viola “on the arm”— meaning violas in the modern sense, held like violins. Joining as a third solo voice is a cello, also from the violin family. The accompanying lines, marked “viola da gamba” and “violone,” indicate bowed instruments that have frets tied to the fingerboard, and are held upright (“da gamba” means “on the leg”). The inclusion of relatively simple viola da gamba parts may have been an attempt on Bach’s part to include his employer, Prince Leopold, who played the instrument reasonably well. In modern practice, two cellos and a contrabass substitute for the viols.
A distingishing aspect of the first movement is its very slow harmonic motion in the tutti sections, with persistent pulses holding each chord steady, while the violas add decorative filligree. If this was one way to avoid straining a less confident player such as the prince, the middle movement solves the problem by eliminating the viols entirely. The violas, over a sturdy stream of quarter-notes from the cello, spin out long lines that rise into the violin’s usual register, all supported by spacious accompaniment from the basso continuo of bass and harpsichord. The finale is another festive dance in the style of a gigue in which the soloists elaborate the main theme with episodes of flowing sixteenth notes.