In order to accept this statement, we have to avert our eyes from the giants in the collective living room of Classical Music. These giants have names, too- e.g.: Bach, Handel, Haydn, Mozart, Beethoven, Schubert, Wagner, Brahms... etc. The reality that no woman of parallel esteem has emerged is something we ought not ignore. Now, the original poster asked: "Has anybody wondered why there are few females in composing and conducting?" At this point, we form our decision tree. We can:

1) Reject the premise of the question- (saying something like "nonsense, boo-boo! There are all kinds of successful women who have emerged in both fields!")

2) Accept the premise of the question (I'd rather not tip-toe around those giants, myself). From this point, we have (roughly speaking) 4 options...
a) say that it's strictly sociological grounds that account* for the discrepency,
b) say that sociology and biology are both in play, but that sociological phenomema predominate.
c) acknowledge the role that sociology and biology play, but conclude that biology plays the greater role. (My position.)
d) assert that it's strictly biological grounds that are responsible for the state of affairs.

Now at this juncture in the narrative, someone should be howling for me to produce evidence for my conclusion. Again, I (like Andante) am not engaging in (to borrow one of Glenn Gould's felicitous turns-of-phrase) in "anything so grand as a THEORY, more like a speculative premise." Still, I'll offer my viewpoint, which is-- based on observation and sense experience-- the numerical disparities between men and women in the Art-music creation field are too great to be accounted for exclusively or even primarily on sociological grounds (e.g.: sexism, infertile environments for development, et al.)

Before I step away, I want to pre-emptively dispense with a "straw man." (Ol' Andante has had to deal with the "straw topiary." I guess by now, he knows what the authors of The Bell Curve must have felt like.)

I am not saying that women are incapable of composing good or even great music, and I'm not saying that women should be discouraged from pursuing composition. (I also believe that Judit Polgar should "keep on keeping on" in Chess, too.).

*Did I mention I love "Preview Post?" I discovered that, when I typed this word the first time, I used one too many "o"s. Well, I thought, better one too many than one too few. That would have been really bad.