What happens when people of different backgrounds meet in the pursuit of work? Ideally, progress.

This fall, the world’s great symphony orchestras will open their 2018-19 seasons. And just as they have for decades, many of them will be sharply segregated by gender.

Men will again make up the majority of brass, woodwinds, and percussion players, and most harpists will again be women.

Quartz at Work examined the instruments played by the musicians of the world’s 20 greatest orchestras, as ranked by the UK’s Gramophone magazine, to understand how gender shapes their composition. Where we could, we looked at the individual musician pages to determine each musician’s gender, and excluded one orchestra that didn’t list individual musicians: The Saito Kinen Orchestra in Japan. When musicians didn’t have their own pages, we searched for their images. If we only had their name, we determined if the name was more likely male of female. (We weren’t able to account for non-binary gendered people.)

We also added three of Gramophone’s “up-and-coming” orchestras, the Sao Paulo State Symphony Orchestra, the China Philharmonic Orchestra, and the Royal Liverpool Philharmonic, for a total of 22. Data were gathered in August 2018.

The results are stark. Of the 2,438 full-time musicians we looked at, 1,677 (69%) were men. But in many instruments, men were even more disproportionately represented. Bassoon (86% male), double bass (95%), and timpani (96%) players are predominately men. Just one of the 103 trumpet players in the 22 orchestras is a woman, and there are no women among the 99 trombonists and 26 tuba players. Only the harp, which is 94% female, is as skewed in the other direction.

The clustering of instruments by gender reflects prejudices that date back to the 19th century, or earlier. Women were discouraged from playing instruments that might distort their facial features (ie., flutes and horns), as well as instruments that required supposedly unladylike postures (like cellos, which are held between the knees), or that were heavy or powerful, says Amy Phelps, a cello instructor who wrote her PhD dissertation about gender discrimination in orchestras.

“The instruments they identified as male are the louder, bigger instruments,” she tells Quartz at Work. “Our society does not want women to be loud.”

There are other reasons for the disparity, rooted in tradition and history. Brass instruments, for example, have a long association with military and industrial bands, particularly in Europe. Those worlds explicitly excluded women.

Jesse Rosen, the president of the League of American Orchestras, says that he and his fellow trombone students in the 1970s “had no use of women playing trumpet or trombone.”

“We thought low brass was the pinnacle of masculinity,” Rosen said. “We thought brass had to be loud and strong, and I doubt we were unique.”

Rosen’s attitudes have changed with the times, and he is now an advocate for gender parity. While elite orchestras are predominately male, the 703 orchestras—professional and amateur—represented by the League of American Orchestras are more evenly divided, with 48% of the players women.

But even if an orchestra is gender balanced, there are still consequences when certain instruments are identified with only men or women, says Rosen. “To the extent that people are meant to feel in anyway bad about their choices, that matters,” he said.

When women are shut out of certain instruments, all of classical music suffers, he said. A woman with the potential to be a great trumpet player may be languishing on the flute because she was steered away from her ideal instrument. “Why should the world of brass playing be denied the talent that’s out there?” Rosen said.

There are economic costs as well. Since principal musicians—who head the various instrument groups—are paid more, the more instruments available to women means the more access they have to the orchestra’s higher-paying jobs. If most women in orchestras play the violin (393 in our survey do, by far the most in any instrument), it means most will be relegated to lower-paying positions.

Professional players often pick up an instrument at a young age, when they are particularly vulnerable to pressure from music teachers, parents, and society’s expectations. Girls who want to play instruments deemed unfeminine often have had to persevere in the face of resistance, well meaning or otherwise.

As a girl in Surrey, UK, Sarah Willis was given the option of the harp, flute, or clarinet, but—inspired by the performance of a visiting instructor—she wanted to play the French horn. As she told theArtsDesk.com, “The teacher at school said, ‘Well we have a horn, but that’s not for you because that’s something for the boys.’ So I said I wanted to play that.” Willis’s persistence paid off. She’s now the sole female brass player at the Berlin Philharmonic orchestra.

Anne McAneney of the London Philharmonic Orchestra is the only female trumpet player in our survey. She began playing the instrument after her school in Northern Ireland split into separate boys and girls schools. “The brass band, which has predominately boys, was rather depleted in number,” she told us. “As I played music, and read music already, they handed me a brass instrument. I said ‘OK.'”

Other girls in the band eventually quit, but she stuck with it, and eventually enrolled at the Guildhall School of Music & Drama, where she now teaches. “I was pretty much always the only girl. The rest were usually males.”

Despite her isolation, McAneney says she never faced overt discrimination, and credits her male instructors with being being supportive mentors. “I’ve never felt out of place,” she said.

McAneney’s orchestra, the London Philharmonic, is one of the few near gender parity overall, with 42% of its players women. The New York Philharmonic and Mariinsky Theater Orchestra have 46% and 45% respectively. Others are particularly poor when it comes to gender balance. The Vienna Philharmonic has the highest imbalance in our study, with 12% of its musicians women. And all of the instrument sections of the Czech, Berlin, and Vienna philharmonics, save for the harp, are less than half female.

While often the gender bias facing women musicians is subtle, occasionally it is blatant. In a famous case, Abbie Conant overcame all the barriers facing a young female trombone player in the 1970s to earn a degree at Julliard and a tryout with the Munich Philharmonic in 1980. She was one of 32 to take part in a blind audition–where a curtain separates the musician from the hiring committee to ward against bias—and was the committee’s top choice for principal trombonist. But after that, she ran up against a dictatorial conductor who demoted her and refused to consider her for solos, according to the Washington Post (paywall). That set up a 13-year battle in the courts to regain her position and back salary she was owed. Conant now teaches at a music institute outside Munich.

The world of classical music is changing, albeit slowly. There have been some high-profile women playing woodwinds and brass, such as trumpeter Alison Balsom (named Gramaphone’s 2013 musician of the year) and Carol Jantsch, who was a college senior when she was named principal tuba player of the Philadelphia Orchestra (she also plays in an all-tuba classic rock cover band).

McAneney says three of the four trumpeters who graduated from London’s Guildhall this year were women, and in a recent recital of Verdi’s Requiem where she performed, half of the eight trumpeters were women.

At Interlochen Center for the Arts, an academy for young musicians in Michigan, students don’t have the same preconceived notions about instruments as older generations, says Kedrik Merwin, Interlochen’s director of music. “It isn’t part of their world view,” he said. “They don’t associate instruments with a particular gender.”

The extreme gender imbalances at the top orchestras are a vestige of the past, he says, in part because many of the male musicians have tenure and hold their seats for decades. In the coming decades, their ranks will be replenished by younger men and women.

Ultimately, the biggest influence on the instrument choices of young women will be seeing other women succeeding at the highest ranks, says Phelps, the cello instructor. She is very deliberate about making sure her students have role models who are women and minorities, because overcoming the prejudices of older generations takes determination. “I still hear horror stories from friends who are student musicians, who are told ‘you sound like a girl’,” Phelps said.