It seems that the more refined music is (and lyrics + music are a refinement over pure music?) the more women that attend the concerts.  Of course this may be because they feel more secure going somewhere because refined music won’t attract rowdy men.

After numerous Jazz and Blues concerts over the last few years my experience is that both genres have a largely mature (in age) audience base.  However, Blues seems to have a much larger male fan contingent than Jazz.  Perhaps because Blues is generally a more aggressive form of music than Jazz?  Jazz is generally more complex too.

My conclusion:  Men like aggression, Women like complexity.

(which explains why it’s nearly always women I see doing Sudoku puzzles on the train whilst the men listen to their iPods. - maybe secretly enjoying vocal Jazz! ;-)