There's an interesting discussion going on over at the Guardian about why there are so few female classical composers. My hunch is that in past times - and still regrettably today but to a lesser extent - it's because women were though incapable of higher reasoning: writing, composing, philosophising etc. Book IV of Paradise Lost makes it clear that Adam's to do the thinking and Eve's 'happier' because she can rely on him. She likes prettiness and flowers and wind and water while he worries about the theology.
Women were also excluded from the formal and informal social networks which produced composers: universities, the master-student relationships which provided informal apprenticeships, access to orchestras and performance commissions. Like their author sisters, I suspect that women composers existed, but didn't get performed. In this regard, at least, pop music is streets ahead, though there's plenty of old-fashioned misogyny there too.
I'm largely talking about the modern period of course: before that, composition was - like most creative work - not something to which an individual attached his or her name. There were - as a Mel Marshall points out - 'squillions' of 'nun composers', one of whom is known to us individually, Hildegard von Bingen (I picked this particular clip so you can compare the advert's treatment of women and medieval culture's respect). Then there were occasional oddities, such as the rather impressive Barbara Strozzi
It's getting better, but there's still a worrying disproportion. So here are some snippets by my favourite female composers.
Her Irish mother Elizabeth Maconchy:
Some Sally Beamish:
and finally some wonderful Nadia Boulanger: