"As I had the good fortune a few years ago to be heard by Your Royal Highness, at Your Highness's commands, and as I noticed then that Your Highness took some pleasure in the little talents which Heaven has given me for Music, and as in taking Leave of Your Royal Highness, Your Highness deigned to honour me with the command to send Your Highness some pieces of my Composition: I have in accordance with Your Highness's most gracious orders taken the liberty of rendering my most humble duty to Your Royal Highness with the present Concertos, which I have adapted to several instruments; begging Your Highness most humbly not to judge their imperfection with the rigor of that discriminating and sensitive taste, which everyone knows Him to have for musical works, but rather to take into benign Consideration the profound respect and the most humble obedience which I thus attempt to show Him." -- J.S. Bach, dedication of the Brandenburg Concertos, 1721.
It's profound just how gracious good ol' Johann had to be in deference. It offends our modern-day sensibilities, grown out of a Lockian liberalism and a strong humanistic drive. But it also points out an important aspect of today's political climate: music has always been sponsored through elaborate systems of patronage by a powerful few; it has not been at the whims of a public free market economy. As such, continued investment of taxpayer dollars in the arts is highly desirable, and will continue to be.
More on the B'Burg Concertos later. But a bit more food for thought: Bach wrote most all of this music specifically with a certain set of musicians at Köthen in mind -- and it's altogether likely that his familiarity with their particular abilities (or lack thereof) likely had something to do with the degree of difficulty of the parts he wrote. Imagine: now, the Brandenburg concertos are treated as some kind of mythical divine gift from a past master (and surely they are!) but this master wasn't merely a master of tones on an abstract tapestry of sound, he was also a pragmatic master of recognizing individual talents and abilities, and playing to personal strengths. Rampant speculation, of course -- I'd like to learn more to properly spin that.