Whether the six Brandenburg concertos constitute a meaningful collection has been the subject of scholarly debate. It is believed that Bach composed them for his famously skilled ensemble in Cœthen, where he served as music director from 1717 to 1723. Dedicated in 1721 to Christian Ludwig, the Margrave of Brandenburg, they may have served as an elaborate musical “resume.” It was no secret that Bach was dissatisfied with his situation at Cœthen and hoped to gain a position elsewhere. Though they didn’t secure him a job, the concertos have long since earned a place among Bach’s most beloved works.

All six Brandenburg Concertos make strong individual statements, and the Brandenburg Concerto No. 5 in D Major, BWV 1050, is particularly bold. In an unexpected move, Bach uses the harpsichord—an instrument usually relegated to the continuo group—as a solo instrument along with violin and flute. Given his stature as a keyboard player, it is unsurprising that Bach played a leading role in liberating the harpsichord from its traditional role as an accompanying instrument. During his time in Cöthen, Bach wrote several sonatas for multiple instruments in which the harpsichord is an equal partner, and while in Leipzig, he innovated the keyboard concerto.

Because of the harpsichord's leading role, the Brandenburg Concerto No. 5 is sometimes described as the very first keyboard concerto—and the reason for this is apparent from the beginning. As the first movement unfolds, the harpsichord's bravura statements become more restless and intense, suddenly erupting in a strikingly virtuosic, unaccompanied episode that transgresses all boundaries of genre, harmony, and rhythm. This remarkable moment has attracted all kinds of commentary, from musicologists who see it as a calculated subversion of social roles to rock musicians who see parallels with their music.

It is possible, however, that Bach’s motivation for pushing the instrument to center stage was somewhat more prosaic. In 1719, Bach traveled to Berlin to purchase a new harpsichord for the Cöthen court built by Michael Mietke, a famous maker known for delicate and beautifully decorated instruments. (It was during this visit that he most likely met the dedicatee of the Brandenburg concertos.) The Brandenburg Concerto No. 5 was probably composed a year or two later, perhaps with this new instrument in mind. After this dazzling opening movement, the ensuing Affetuoso features the soloists alone in lyrical counterpoint. The concerto concludes with a dancelike Allegro, in which the harpsichord again dominates in torrents of brilliant figuration.