Brandenburg concertos

The six Brandenburg concertos (BWV 1046-1051) by Johann Sebastian Bach are a collection of chamber music works ("avec plusieurs instuments") presented to the Margrave of Brandenburg in 1721, but probably composed much earlier.

By 1721, Bach's third year as court organist at Anhalt-Köthen, he was becoming restless and began looking for career opportunities outside the small town. In March, he assembled these six concertos and presented them, by way of a job application, to the Margrave of Brandenburg. The concertos have little in common; the dedication page Bach wrote for the collection merely indicates they are six pieces for several instruments. Indeed, the six works attempt to use as many different combinations of common instruments as the composer could think of. The concertos have been called a "microcosm of Baroque music," purportedly because they exemplify the potentials of the musical style of the era, in all of their varieties—in only six concertos.

The First Concerto in F major calls for two French horns, three oboes, a bassoon, and a violine piccolo as well as two violins, a viola, and a basso continuo for accompaniment. This varied group of instrumentalists presents a dance-like concert. This concerto is the only one in the collection of six with four movements, rather than three. An earlier version of this concerto survives as a sinfonia, BWV 1046a.

The Second Concerto, also in F major, is in the form of a concerto grosso, and calls for a somewhat simpler but rather unusual ensemble of piccolo trumpet, recorder, oboe, and solo violin, with two violins, a viola, and a basso continuo again accompanying.

The Third Concerto in G major is often cited as the prototype of the modern string quartet as Bach here calls for only string instruments. The three violins, three violas, and three cellos are accompanied by a basso continuo. The dazzling third movement appears in many movie and commercial soundtracks.

The Fourth Concerto in G major—for violin and two flutes accompanied by two violins, a viola, and a basso continuo—uses these common instruments in uncommon ways; the solo violin part actually mimicks the continuo accompaniment at times, moving what is traditionally foundation, to the treble register.

The Fifth Concerto in D major for flute, violin, and harpsichord, with violin-, viola-, and basso continuo-support, makes use of a very popular chamber music ensemble configuration (flute, violin, and harpsichord). Bach, himself a keyboard virtuoso, included a stunning harpsichord cadenza in this concerto, prefiguring the piano concerti of Mozart and Beethoven.

The Sixth Concerto in B-flat major sets two trio groups against each other. On the one side sit the "modern" violas (two of them) and cello, while on the other side of the stage sit the "old-fashioned" violas da gamba and double bass. These opposed low-register trios present a series of call-and-response motifs that is totally without precedent in the musical literature.