Forgetting the words when you’re singing in the shower is no big deal. Forgetting the words to the United States National Anthem when you’re singing at Yankee Stadium could be something else.

To be clear, Irish tenor Ciaran Sheehan didn’t forget the “Star Spangled Banner” lyrics when he performed it before a Yankees’ game, but that didn’t mean it was automatic. The world-renowned vocalist went over the lyrics “something like 50 times” before he took the field. Former Yankees legend Gene Michael didn’t exactly build his confidence. “Stick” being “Stick” ribbed Sheehan like the tough-as-nails shortstop he was a few minutes before the moment of truth.

“Hey,” Sheehan recalls Michael telling him as he was about to be introduced. “Don’t forget the lyrics.”

Sheehan is clutch and came through and Lehigh Valley concert-goers can see him come through with his rich voice and sterling stage presence as he performs with the locally-iconic Allentown Band during the “On Broadway” concert, 7 p.m. July 28, Miller Symphony Hall, Allentown.

The songs are familiar and should go down like a tall glass of lemonade on a hot summer day. The composers, Bernstein, Rodgers, Christensen, Schonberg and Webber and others, are legends.The theatrical productions, “Phantom of the Opera,” “West Side Story,” “Carousel,” “Miss Saigon” and others, are staples of mainstream culture.

“I’m very grateful to be able to perform these songs. It’s thrilling to perform them with a bigger sound of The Allentown Band,” says Sheehan in a phone interview.

“Almost everyone knows these songs,” says Ronald Demkee, conductor of the 45-member Allentown Band. “Many in the audience that night may have seen Ciaran on Broadway.”

The acclaimed actor, singer and Broadway tenor gets around. His resume is impressive and extensive. At the top of that list could be that he’s played the Phantom in the “Phantom of the Opera” more than 1,000 times on Broadway and in Toronto.

His rise to show-tune fame wasn’t exactly planned The Irish-born, Lawrenceville, N.J.-raised Sheehan came from “a blue-collar family.” His exposure to Broadway shows such as “West Side Story” was limited to “what was on television.”

As a teenager he was in “a heavy metal band at the Jersey Shore” and was more enthralled with Robert Plant than Luciano Pavarotti. He learned to love theater later when he was in college studying to become an electrical engineer.

Sheehan always had one thing you can’t teach: talent. It was that talent that allowed him to start performing with the Irish Repertory Theatre in New York City after his studies concluded. “About five to six months” after meeting Broadway director Harold Prince, Sheehan was performing on Broadway in the production of “Les Miserables.” Prince later cast him in “Phantom.”

In spite of all the accolades and the fame, Sheehan remains a student of his craft and is still “taking voice lessons.

“I do really enjoy the journey a lot,” he says. “For example, I am fascinated how our body has an effect on our voices ... I just love the work.”

Sheehan is humble and thankful he’s able to make living performing as a vocalist and bring that a youthful enthusiasm to every show or performance.

Once Sheehan performed the National Anthem at Giants Stadium and was blown away by the awesome roar of 75,000.

“You can just feel the energy,” he recalls. “I can understand how football players get so pumped to go out there and play.”

True to form, Sheehan remembered the words to the “Star Spangled Banner” even without Gene Michael’s vote of confidence.

Tickets: Miller Symphony Hall box office, 23 N. Sixth St., Allentown; allentownsymphony.org; 610-432-6715