Johann Sebastian Bach most likely completed his Brandenburg Concerto No. 5 in D major, BWV 1050, in 1721. This work is the fifth of six concertos the composer dedicated to Christian Ludwig, Margrave of Brandenburg. The offering was likely a sort of application for employment; Bach got no response, but these pieces have become some of his best-known material. Every one of the concertos is distinct, as are the composer's sets of suites and partitas. Hearing the fifth concerto in the context of the rest of the set makes it clear that, apart from Bach's inimitable strength as a contrapuntist, the key to his ability to make music that is both sublime and entertaining lies in the fact that in his hands, everything is elastic. No other composer of the Baroque era could write through the constraints of form as if it was not there at all. Bach saw more options than anyone else, in form and in influence. The way he blended the Italian sound into his own in these concertos ennobled both Italian and German music. The scope of his vision and his relentless invention, making everything he wrote new, frustrates any attempt at comparison.

This fifth concerto is scored for flute, solo violin, obbligato harpsichord, and strings. It is the only one of the six pieces to have any solo material given to the harpsichord, which is part of the continuo throughout the other works, filling out the harmonies. What is quite bizarre and beautiful about the opening movement is the way the solo instruments and string ensemble seem to be muscling in on each other's musical functions. More specifically, the ritornello is almost carried away by the soloists although it is normally the territory of the tutti ensemble. The harpsichord seems to be holding the work together, and there are episodes in the second half of the movement where everything has ground to a halt except for the harpsichord. At the end of the movement, the other soloists actually support the free-flowing harpsichord line. It is a sort of divide-and-conquer movement, with tutti versus soloists, and also soloists against soloists. The harpsichord wins. No one wrote music with this sort of free play of function before Bach.

The following two movements, briefer than the first, form an admirable contrast. The second movement is for soloists only, somber and cooperative. Though it is intimate and free of the first movement's tension, it is the most concerto-like movement in the traditional sense. This is a colossal irony, considering how the tensions of the concerto form were exploded in the first, which is as much a departure from the form as it is an adherent. The final movement is a charming dance, a lively gigue with fugal powers.

This arrangements is for standard string quartet with an optional bass part.