In the 1970s, something discordant was noticed about the top five symphony orchestras in the US. Fewer than 5% of the musicians were women.

This brought the selection process under scrutiny. The musicians in an orchestra were picked by the director, and although plenty of women were applying, those who got jobs were often male students who had studied with the same group of teachers. So auditions were made blind - applicants played behind a screen. By the late 1990s the top five orchestras were 25% female.