> > uniqueness of each tonal center by giving it a particular sonority?  In
> > other words, why didn't Bach simply keep the C#-major prelude (WTC I) in
> > C major?  Or better yet, why not transpose the C-major prelude up a half
>
> And, what about the "French Overture," which was written in C-Minor,
> but published in B-Minor, and is now performed in both?  Isn't there
> a difference in the 'feel' of those two keys?  (But, if there is a
> different feel to the two keys, and if the story about Bach's allowing
> it to be published in B-Minor is correct, didn't Bach care?)
>
 
I think Bach made both of these transpositions as an expedient.  In both
cases, he wanted to create a whole which was larger than the sum of its
parts.  In WTC, the scheme of a P&F in all keys was the motivator.  He
needed a prelude in C#, and took one in C that worked and transposed it
up.  In the case of the Ouverture, he was completing a key sequence begun
in Clavierubung I: Bb, c, a, D, G, e.  (Think of the "wedge" fugue!).  To
logically continue (and complete) this sequence, Clavierubung II uses the
keys F and h (with dominant F#).  In Clav II he was also demonstrating
(and, in a sense polarizing) the Italian and the French in music, and
using this scheme results in two keys which are as remote as possible
(major vs. minor, and a tritone apart).  I think this scheme was far more
important to Bach than the affect/effect of the key difference.  We have
gotten used to hearing/playing Bach's works in certain keys, and there is
certainly some significance to the keys utilized in certain works.  (There
seems to be a G-Major "style," for example.)  But, in other places, Bach
transposed to suit his purposes, without apparent attachment to specific
keys for specific works.
 
Just as an aside, can you imagine Louis Couperin's Pavanne in f-minor?
Or, Beethoven's 5th Symphony in b-minor?
;-)
 
Dave Kelzenberg