So Richard Strauss was married to a soprano. I'm sure neither where or what she sang, nor whether whatever she may have had of a career continued after she married. I do know, however, that a good portion of his songs (many of which are for soprano to begin with) were for her.
I wouldn't necessarily call Strauss a "feminist" - I'm really not sure - but his opera, "Der Rosenkavalier" has some interesting points in it to that flavor (though Hugo von Hofmannsthal was the librettist). I first came across the music some years ago while playing in a summer orchestra program (during which the orchestra prepared one or two major works and performed it at the end of the week); Strauss took the major themes from the opera and condensed it into an orchestral suite shortly before he died. The conductor that week had assigned each of the sections to research a certain aspect of the work (the section who completed that the most quickly and accurately was dismissed for lunch first on Friday - I don't remember). The bass section was assigned the synopsis. I (being both the youngest and most excited out of the seven bassists) went to the library immediately and took notes. Golden stars for that week, for sure.
The basic story (in a very short and Cara-fied version) is that two kids fall in love but the girl is engaged to this old fat man who really does not treat her very well. Sophie (the young girl) and Octavian (the young boy, sung by a mezzo, something Strauss deliberately chose for the two reasons that the character is so young and so that some "fat old tenor" would never end up playing the role) devise a plan to get her out of the marriage. This is made interesting by the fact that Octavian and the Marschelin ("Princess" in the English versions) have been having an affair and Octavian is ultimately forced to choose between the two.
Okay, I know those paragraphs haven't really at all been about "women in music." But here's my thing about this opera: a third of the way into second act, Sophie realizes she doesn't want to marry the fat old guy, having not only fallen in love with Octavian, but quite literally having been "looked at like a horse" by the fat old guy. What's more, directly preceding this realization, she is shown to be quite the firecracker while making small talk with Octavian, venturing into topics which earn her many a nasty glare from her (for lack of a better term) nanny.
After Sophie's realization that she'd rather not enter this marriage, she asks Octavian for help - pretty typical of an opera, right? Girl is betrothed so some guy. Girl asks local hero to save her. This is where your typical opera with this sort of story ends: Octavian agrees to help her on the condition that she stand up for herself first (reasoning that there is nothing he can do until she makes it known that she is not happy with the arrangement).
Maybe it's not such a big thing, I don't know. Every time I come across that particular scene I am shocked; Octavian sings, "for you and me you must defend yourself and remain what you are." For the last three words ("was Sie ist"), Strauss first introduces Octavian's horn call, and he sings those words for the last part of the phrase. He is encouraging her to stand up for herself rather than be "the man" and do it for her. It's also in the following duet between the two when they switch from the formal to familiar forms of 18th century Viennese German (which also means that Sophie begins to address Octavian directly rather than saying things like, "Would it please him to sit down?").
...on the other hand, when I first saw this opera, the old man next to me said that he'd paid to see an opera, not some "lesbian sex scene". Eh.