You could exhaust the dictionary looking for the perfect words to describe coloratura soprano Lisette Oropesa’s performance at Tucson Music Hall Saturday night.

“Arresting.” “Stunning.” “Magnificent.” “Sublime.” Extraordinary.” They come to mind alongside “brilliant,” “breath-taking,” ‘divine” and “fearless.”

It was all that and much more when the Louisiana native sang the title role of Arizona Opera’s production of “Lucia di Lammermoor.” Perhaps the greatest testament to the enormous talent she displayed was the fact that she left us speechless.

And she made us squirm. Her mad scene was so realistic I found myself fidgeting in my seat, and from the chorus of creaking chairs around me, I suspect I was not alone.

This is where “fearless” perfectly sums up her performance. She checked her ego at the door and allowed herself to go from striking beauty to unkempt mess — complete with nattily teased hair, bloodstained hands and a pure white wedding gown smeared with blood. It was not attractive.

And neither was her expressions, going seamlessly from schoolgirl giddy to darkly distracted. She invited us to peer into a mind that was vacillating between fantasy and reality until all that was left was helpless mush.

Oropesa’s Lucia did not go mad suddenly; under director Fenlon Lamb, it was a gradual progression that started when we were first introduced to Lucia in the garden as she saw the ghost of a woman who had been killed by her jealous lover and left to rot in a well. Lucia sees the apparition as a sign that she should stop seeing Edgardo, the sworn enemy of her brother Enrico.

Bringing the ghost — wearing a stained dress and looking gray as death — to life added layers of terror to the opera, and went a long way to convince you Lucia was slowly going mad. The ghost reappears several times, seen only by Lucia. And when Lucia finally did go mad, she looked a lot like that ghost.

But it was Oropesa’s voice that commanded attention and got it. Her coloratura runs were crystalline and warm, the trills ornate without being showy. Her mad scene was achingly beautiful, with breathtaking and expressive cadenzas particularly her duet with the flute. There were times when you were tempted to applaud before she had finished her aria. And when she did finish, the applause was prolonged, with a few bravos and hoots from the audience filling two-thirds of Music Hall thrown in as exclamation points.

Oropesa was surrounded by an equally wonderful cast not the least of which was the Arizona Opera Chorus. These folks are the unsung heroes of Arizona Opera, and in “Lucia,” they were the bona fide stars. In the opening scene, the chorus outsang Normanno (tenor Samuel Levine), who was having difficulty projecting with any authority. For much of the scene, even when he was singing solo, you couldn’t hear him.

Mark Walters as Lucia’s deceptive brother Enrico showed off a commanding baritone, while tenor Joseph Wolverton as her true love Edgardo flexed muscular vocal chops that never wavered.

The orchestra, under the baton of Steven White, was eloquent and powerful. Throughout the nearly three-hour performance, the orchestra sounded like it was singing, particularly during the final act when Oropesa matched cadenzas with the flute and other instruments.

This was Oropesa’s second Arizona Opera appearance. She earned a similar ovation for her role in “Rigoletto” in 2008.

“Lucia di Lammermoor” repeats at 2 p.m. today at Tucson Music Hall, 260 S. Church Ave., with soprano Stacey Tappan in the role of Lucia.