There was plenty of chromatic alteration running around before
Bach hit the scene. Bear in mind that the Spanish cross-strung
and Italian triple harps were invented in the 16th century to deal
with chromatic alteration in late renaissance music.
(Range is not really the issue--my cross-strung harp only has
a four-octave range, even though it's five feet tall; a lot of what
I play stays within a compass of three octaves. But I really
need those chromatics!)
The rules of counterpoint (specifically, musica ficta causa
pulchritudinis) routinely introduced chromatic alteration at
cadences as early as the 14th C. By the 16th C., musicians
were also using chromatic alteration for expressive purposes.
By the late baroque, the wayward chromaticism of the late
16th and early 17th century had been disciplined to the service
of functional harmony; Bach (along with Telemann, Handel,
etc.) represents the culmination of that tradition, not its source.
(Not to mention the fact that hook-harps, which used a
mechanism not to dissimilar from the modern lever harp,
predate the invention of the pedal harp. Were the people
who pioneered the use of levers on 20th C. folk harps
familiar with the German hook harp?)
And finally, while Bach was certainly a magnificently
literate musician, he was more famous in his own day
for his improvisation.
Bill McJohn
billmc@microsoft.com