Lucia Lucas has taken one of the most difficult paths to her American professional opera debut.

She moved to Europe a decade ago as Lucas Harbour, established a career as a baritone in regional houses, then decided in 2013 to transition to female. Now a transgender baritone, she will make her U.S. debut as the title character in Mozart’s “Don Giovanni” at the Tulsa Opera in performances Friday and Sunday.

“I’m sure other houses will be watching to see what happens,” she said.

Now 38, Lucas grew up in Sacramento, California, studied horn and voice at Cal State Sacramento and then did graduate work at the Chicago College of Performing Arts. Her coach, baritone Richard Stilwell, suggested a move to Germany.

Tobias Picker, the composer who is Tulsa Opera’s artistic director, auditioned her in February 2018 for a planned transgender opera after discovering Lucas’ clips on YouTube and sending her an email.

Lucas sang from Picker’s own “Thérèse Raquin” in Picker’s Manhattan living room, and he decided on the spot to offer her “Don Giovanni.” Director Denni Sayers has Lucas use different disguises, employing the singer’s ability to present masculine and feminine.

“It’s a great dramatic baritone voice,” Picker said. “It has depth of emotion and it has enormous power.”

Lucas long felt uncertain as a male.

“As soon as I knew that there were boys and girls, I knew,” she said. “I didn’t have terminology for it. It was mid ’80s, so it was a little difficult. If I had a phone with Facebook and Instagram and all the things that exist now, I would go: This is me. I would find a video and show my parents and say: This is me. Please help me.”

Harbour sang at Germany’s Deutsche Oper Berlin and Italy’s Teatro Regio Torino in 2009-10, spent the following season in Heidelberg, then shifted with artistic director Peter Spuhler to Karlsruhe and stayed through 2015-16. At first the roles were small, but some were led by famous conductors, including Wagner’s “Tannhäuser” with Semyon Bychkov in Italy.

Lucas made the decision in November 2013 to transition and started taking estrogen and anti-androgens in July 2014. Facial feminization surgery followed that September and gender confirmation surgery in 2016.

She worried how the transition would be received by administrators, colleagues and audiences.

“In the beginning, it was scary,” she said. “And I think that there are people who are still not necessarily on my side and may never be on my side. But what are you going to do? You gravitate towards the people who like you and you try not to worry about the people who don’t.”

By 2016, her roles had grown to the toreador Escamillo in Bizet’s “Carmen” in Karlsruhe and the four villains in Offenbach’s “Les Contes d’Hoffman (The Tales of Hoffmann)” at Opernhaus Wuppertal , a staging that had her start as female for Lindorf, become male for Coppélius, then switch back.

“The audience was so thrilled. There was such an energy and tension in the room,” said Berthold Schneider, Wuppertal’s artistic director. “She immediately won the hearts of the audience.”

Lucas’ wife, Ariana , is a 33-year-old contralto who is a company contract singer with the Badisches Staatstheater Karlsruhe. They met in college when Ariana crashed a Halloween party.

In transitioning, Lucas never thought about trying to raise her voice.

“I would love to wake up and be able to sing Brünnhilde, but that’s not how it works,” she said of the lead role in “Die Walküre.” ”Doing a Wotan is probably going to pay more than an Erda or Fricka.”

Mezzo-soprano Adrian Angelico is the most prominent male transgender opera singer, performing roles such as Cherubino in Mozart’s “Le Nozze di Figaro (The Marriage of Figaro)” and Octavian in Strauss’ “Der Rosenkavalier.”

Given the scarcity of top Verdi and Wagner baritones, Lucas hopes to be hired by bigger and bigger companies. A role debut for Verdi’s “Rigoletto” is planned for 2020-21. She is scheduled for her English National Opera debut next fall in Offenbach’s “Orpheus in the Underworld.”

And then there is the role Picker auditioned her for: He has the rights to “The Danish Girl,” a novel by David Ebershoff about a sex reassignment surgery in the 1920s, one adapted into a 2015 film directed by Tom Hooper. Picker will compose and Aryeh Lev Stollman will write the libretto.

First is this weekend. While Lucas’ mother has seen many of her performances, her father planned to make the trip to Oklahoma. Lucas’ parents divorced decades ago, and she hasn’t seen her dad in 10 years. As if an American debut weren’t enough pressure.

“I haven’t seen my dad in a very, very long time, definitely since I came out and quite a bit longer than that,” she said. “We just stopped talking. It’s just like birthdays and holidays.”