A Tale of Two Bachs... and Books
The first, Evening in the Palace of Reason [Hilariously, the Harper-Collins blurb says the meeting took place in 1757, long after Bach had died, instead of 1747] by James R. Gaines, and the second is the monumental Johann Sebastian Bach: The Learned Musician by Christoph Wolff, probably the world's foremost musicologist specializing in the life of Bach.
I said they are very different, but I might as well have said that they could hardly be more different. Evening in the Palace of Reason centers on the lives of Frederick the Great and J.S. Bach as they lead up to their meeting in 1747, while The Learned Musician is all about Bach. I mean, all that is known and that can be surmised about Bach. The former is an engrossing, fast paced read, while the latter is exceedingly detailed - sometimes even excruciatingly so - but deeply satisfying in a different way, especially if you are a serious student of the music of Bach, as I am, or a very curious and already well informed amateur.
Interestingly, the two authors have radically different takes on the 1747 Potsdam meeting as well as the resulting work, the famous Musical Offering. In Gaines' dramatic and humorous look at the situation, Frederick and Bach's son Carl Philipp Emanuel conspired together to embarrass the old man by coming up with The Royal Theme, which allows for virtually no stretti. According to him, Bach's ass was chapped by the obvious ruse, and The Musical Offering was Bach's revenge. Wolff, on the other hand, views Bach as a peace emissary (!) just months after Frederick's Prussian army had occupied his little burg, and The Musical Offering as a pious gift to the king.
Who is right? It's obviously impossible to be completely sure, but even the picture Wolff paints of Bach is of a larger than life character who did not suffer fools gladly, and who took perceived affronts to his music very, very seriously, so I'm inclined to side with Gaines. Besides, it makes for a much more interesting story.
So, I would recommend Gaines' book to anybody interested in Bach who likes fast and fun reading - his description of Frederick's "gay in all senses of the word" court is particularly humorous - but a word of caution is in order for Wolff: This is the deep end of the musicological pool here, and even I found parts of the book an epic slog (As someone who has analyzed in excruciating detail a lot of Bach's music, and who can actually, you know, compose in those styles, I found his descriptions of Bach's compositional approaches particularly eye-roll inducing).
Bottom line, though, I'll undoubtedly read Wolff's book again, while I think once through Gaines' tome is enough.