When Fort Worth-native Aaron Casey's mother encouraged him to sing at a young age, he said no. When she pushed him to join the Texas Boys Choir, he fought back. And when he fulfilled music requisites in junior high school, he couldn't run fast enough from class.

But alas, mother knew best.

Casey, now a 19-year-old voice major at University of Houston's Moores School of Music under the tutelage of Joseph Evans, has been rubbing elbows with vocal mega stars. He was chosen to participate in HBO's YoungArts Masterclass, twice: First studying with virtuoso Bobby McFerrin at Festspielhaus Baden-Baden, Germany's largest opera house in an episode filmed last year and with diva Renée Fleming in Chicago and New York last month.

The episode where he sings for Fleming, is set to air on May 28 at 6 p.m. Casey will travel to the Big Apple for the premiere screening and dinner at the Museum of Modern Art. The other documentary episode is slated for broadcast sometime later this year.

The series focuses on young aspiring artists and pairs them with a doyen of repute in their respective field. Through coaching, interactions and performances, HBO hones in on what it takes to flourish from student to professional.

Master classes are notoriously difficult for young musicians as the open format exposes artistic, emotional and technical weaknesses. For the inexperienced artiste, that can lead to feelings of inadequacy and insecurity.

"People are watching you, and it's easy to fall into the trap of worrying about what others may think, " Casey says. "But to perfect my craft, to be the best artist I can be, I have to be willing to be vulnerable. I want the help, and they (Fleming and McFerrin) want to make me a better artist."

Casey's TV journey began at the 2011 Young Arts Week, an immersive summer music institute hosted by the National Foundation for Advancement in the Arts in Miami. He was approached by Young Arts officials who encouraged him to apply, alongside 150 hopefuls, for a spot on camera.

"From Bobby I learned that what happens on stage, stays on stage," he explains. "Once you are off the stage, it's done. I needed to learn that so I wouldn't dwell on things that didn't turn out as I wanted."

Casey's repertoire for McFerrin included Debussy's "Romance," a classical version of the spiritual "Swing Low, Sweet Chariot" and "His Eyes on the Sparrow."

Fleming taught him to perfect technique in the practice room. But during performance, she suggested he focus on artistry and trust that the technical elements would fall into place. For her Casey sung Handel's "Ombra mai fu" from Xerxes and "It Ain't Necessarily So" from Gershwin's Porgy and Bess.

"The experience changed me musically and personally," Casey says. "Both Bobby and Renée are so poised, elegant and humble. Above all, I want to stay grounded in humility."

If he could have it all, Casey's dream is to become a world-renowned operatic tenor. But most important, if he reaches stardom, he wants to give back to the same organizations that changed his life. He's most comfortable singing Mozart and Handel, but he hopes his voice develops to take on the opuses of Verdi.

Casey performed in Moores Opera Center's production of Daron Hagen's Amelia, Strauss' Der Rosenkavalier and Verdi's Falstaff. He also sings in the Concert Chorale. This summer he is off to partake in the Harrower Opera Workshop at Georgia State University and the Toronto Summer Music Festival.

Watch the video trailer (above) for a sneak peek at Renée Fleming in HBO's Masterclass with Aaron Casey and three other talented youngsters.