This might sound odd, but Johann Sebastian Bach and the Beatles have a lot in common. Both were ambitious from the very beginning of their careers, almost to the point of arrogance (Bach also felt he deserved a place at "the toppermost of the poppermost"), both were very conscious of money to the point of greediness, and both engaged in some pretty unseemly actions to get to their positions of prominence (Bach certainly had some getting-rid-of-Pete-Best moments). And of course, both are famous to a ludicrous, genre-defining, platonic-ideal level; you could say the Beatles were the Bach of rock music and that Bach was the Paul McCartney of eighteenth-century Germany.
Bach was simultaneously very religious—he held some sort of musical position within the Lutheran church for pretty much his entire life and nearly all of his music was spiritual in theme—and yet he was also very much of this world; he had 20 children (via two different wives), spent an inordinate amount of time job-hopping to get higher and higher salaries, and suffered from over-weaning pride that often got him in trouble with his superiors and rubbed his peers the wrong way.
But all of that is forgotten when you hear his music. I'm by no means a Bach scholar, but I have loved his music for many years and still find myself moved when hearing a piece of his music that I've heard dozens of times before. When you hear his music, even knowing how unlikable of a human being he was, all is forgiven.
From a literary standpoint, this biography is nothing amazing; it's kind of a Cliffs Notes version of his life, with not very much detail. But it's a good starting point for deciding if you want to know more about his life. But I've decided I don't. I'd much rather just go listen to his motets.