One was her stand-in performance with the Kentucky Opera in 2008 when a cold sidelined the main female lead playing Desdemona in Otello. As the understudy, Moura took over on short notice to finish the final acts before a delighted audience.

Another will be this week as she takes stage for two roles in UofL Opera Theatre’s presentation of Puccini’s Suor Angelica and Gianni Schicchi. But it is most special for her as her daughters, ages 6 and 7, will play the son in the closing scene of Suor Angelica.

The girls won’t sing in their debut performance, but their mother will. She will sing one of opera’s most beloved arias, O mio babbino caro, as Lauretta in Gianni Schicchi.

It is very difficult with its octave jumps, Moura said.

The skill necessary to master them will make audiences find it hard to believe that Moura went six years without singing.

Moura left her native Brazil when her husband came to the United States to complete his master’s degree. While he studied, she devoted her time to the children and family needs. But when he completed his degree, it was her turn to pursue a passion and talent mostly heard by those with whom she attended church.

I was accepted into the master’s program at Campbellsville University and then accepted as an intern chorus member after auditioning with the Kentucky Opera, Moura said.

Having completed her master’s at Campbellsville and enjoying the experience of professional singing, Moura decided to work toward another master’s in vocal performance at UofL. As the first UofL graduate student in the Studio Artist Program at the Kentucky Opera, she understudied professional singers along with her work on campus. This led to the storybook performance in Otello.

The Studio Artist Program, now is in its third year, provides opportunities not offered in most college settings, said Edith Davis Tidwell, UofL voice professor and liaison with Kentucky Opera.

Moura’s voice is one of beauty, with no compromise with the professional cast when she performed, Tidwell said. The opera program is intense but it allows us to raise the bar on attracting students with strong voices and to develop them to a higher level.

That is certainly true for Moura. One of the top seven at the Czech and Slovak Voice International Music Competition of Montreal semifinals last fall, she will begin her doctoral studies at the University of Kentucky this fall, helped by her success in this year’s Lexington’s Alltech Vocal Scholarship Competition.

Moura will attend the American Institute of Musical Studies (AIMS) in Graz, Austria, next summer in addition to performing in two operas with the 2011 Rome Festival. There she will take on the role of Mimi in Puccini’s La Boheme, one of the most important roles for sopranos.

This summer Moura plans to work on her fluency in languages while back in Brazil where she will perform some solo concerts.

German is difficult for me, while French is easier to sing, she said. I love to sing Italian, but it is closer to my Portuguese, and I have to concentrate and not relax to avoid mixing some vowels.

No matter what the language, Moura will continue to hit the high notes.

The UofL Opera Theatre presents Giacomo Puccini’s Suor Angelica, a heart-wrenching tale of piety, passion and penance with soaring melodies, and Gianni Schicchi, a satirical and funny farce, 8 p.m., April 9 and 10 at the Brown Theater, 315 W. Broadway. The one-act operas will be sung in Italian with projected translations. Mike Ramach, directs; Kimcherie Lloyd conducts the University Symphony Orchestra.

Tickets are available through the Kentucky Center box office by calling 502-584-7777 and online or at the door, as available. Prices are $20 for general admission and $10 for UofL affiliates.