This man with twenty one sons is gray to me. Not only because his hair were gray, but also becuase of the fact that I don't know him much. (So this wallpaper certainly suits him!)
Bach's huge collection of works stunned me, and I really wonder how could one produce so efficiently (both in terms of compositions and prodigies). His work covers every and each area of music of his time, from solo to concerto, and from vocal to instrumental. He was principally an organist who, at his time, was natural to write many keyboard compositions (which includes the arrangements of Italian Concertos). He was also a violinist and concert master, and the position as a chior master charged him to compose and direct a new cantata each month, which could attribute to the enormous number of his works.
I learned from my volume of Well-Tempered Klavier that Bach wrote very accurately what is to be played and yet, left his performers free on how to play it. He insisted that every single note has its own meaning and thus, each of them has to be sung out as in the "cantabile style" he suggested.
Well, this is all I know about him. In order to give you little idea how enormous his collection of works is, here I'll give you a tiny part of his keyboard compositions. For complete list of his works, please refer the the gorgeous Bach Central Station.
Bach's incomplete list of works
Some other fantastic links on J.S.Bach