Nevertheless, Sacramento-born-and-raised baritone Lucas, who decided to keep singing with her booming, low-voice type after her physical transition rather than trying to retrain her voice to sing soprano or mezzo roles, is rising to the very top of her profession.

In May, she became the first trans singer to perform a lead role in a classic operatic work in the U.S. when she starred in "Don Giovanni" with the Tulsa Opera in Oklahoma.

In October, she will play a lead role with the English National Opera in London.

Yet Lucas said she often dons fake facial hair and standard menswear for auditions to prove she can play roles that normally go to cisgender male performers.

"A lot of people are really confused because they have 'Ms. Lucia Lucas' on their paperwork as a baritone," Lucas said. "But I'm presenting with a beard in masculine attire."

Hormones & the Human Voice

When it comes to perceptions around gender transition, most people tend to focus on external physical changes.

But taking the male hormone testosterone doesn't only tend to increase body hair and muscle mass. It also lowers the voice.

"Testosterone thickens the vocal folds," said UCSF voice speech pathologist Sarah Schneider, who specializes in working with transgender singers.

But learning a new lower-pitched way of speaking and singing often comes with enormous challenges.

"Some people describe it as feeling locked in," Schneider said. "They're not quite sure how to navigate the lower voice."

Schneider said surgery for lowering vocal pitch exists. But few people go that route, because of the lowering effect of testosterone.

It’s a completely different story for people taking estrogen.

"For trans females, taking female hormones does not actually change the voice," Schneider said.

She said surgery on the vocal folds is a possibility for people who want to sing higher. But it’s a major risk.

"The outcomes are not always predictable," she said. "And we don't know if it's going to impact that accessibility to the upper range."

It's possible to develop a higher speaking and singing register with careful training and consistent practice.

Schneider said the best way to keep the voice healthy through the gender reassignment process is to keep using it — without pushing too hard.

"It's just a matter of looking at it like training," she said. "We work on these different muscle patterns so they feel accessible."

Opera Companies Begin to Address Diversity

Opera's diversity and inclusivity challenge extends well beyond transgender singers. As an African American, Bay Area soprano Breanna Sinclairé is especially troubled by this reality.

"In the classical world, there are still other issues that we have to deal with first before we get to the transes, because there is a history of racial discrimination," said Sinclairé, who abandoned the tenor range she was mostly forced to sing in while growing up, and has focused on extending her voice upward as a soprano. "It’s not a diverse genre of music. And I don't see many African Americans or many Asian or Latino women playing lead roles."