This Guardian article, published a few weeks ago, discusses the impact of clothing on how female musicians' performance is evaluated. But it also refers to those interesting earlier studies of orchestras:
I have always loved those blind audition studies! Imagine how the current anti-feminist commentators (I'm looking at you, Hoff Sommers ) would have "explained" the dearth of women in the early 1970s orchestras in the absence of those studies:
In the world of music, assessment of performance goals can be restricted to make individuals broadly comparable, and so there's a reasonably long tradition of the field being used as a test tube for bigotry. In the 1970s and 1980s, in an attempt to overcome biases in hiring, most orchestras changed their audition policy, and began using screens to conceal the identity of the candidate.
Female musicians in the top five US symphony orchestras rose from 5% in the 1970s to around 25%. This could have been due to wider societal shifts, so Goldin and Rouse conducted a very elegant study, Orchestrating Impartality: they compared the number of women being hired at auditions with and without screens, and found women were several times more likely to be hired when nobody could see that they were a woman.
What's more, using data on the changing gender makeup of orchestras over time, they were able to estimate that from the 1970s to 2000 – the era which shifted from casual racism and sexism in popular culture, to more covert forms – the trend towards greater equality was driven simply by selectors being forced not to see who they were selecting.
Perhaps women just don't want to hold jobs which require traveling! Women may not be as good musicians! Motherhood is incompatible with evening work! Orchestras require male clothing!
And it would have been tricky to prove that any gender discrimination exists without those screens and the impact their use had.
Note that when I use the term "gender discrimination" I don't mean that the people picking new players for the orchestra are necessarily misogynists or even opposed to women as such, although they may be. Rather, I mean that the gender of the musician exerts an independent effect on her/his chances of getting hired, and that effect works against female musicians.
But then the orchestras in some other countries seem to hire no women at all.
Link to the Goldin-Rouse study.