Leaving all our various preferences and rants aside, am I correct in thinking
that single manuals were much prevalent than doubles, at least until the tail
end of the harpsichord industry? (I base this on what I have read about extant
instruments and iconographic evidence.) So much of the music that we play
would ordinarily have been heard on a single. This is not an assertion of an
aesthetic value judgement, merely an attempt to get historical facts straight.
I have also noticed that my friends who prefer 17th-century music tend to like
playing on singles, while those who feel more at home in the 18th century like
doubles. Then perhaps there is some connection between aesthetic preferences
and types of instruments, though I'm not sure what. Bach, of course, usually
appeals to both 17th and 18th century fanciers so it is not surprising that
our debate has centered around his toccatas!