From Long Island pizza delivery boy to performing all over the world, Sal “The Voice” Valentinetti says appearing on “America’s Got Talent” transformed his life.

In January, he will return to the NBC hit reality TV show for its first-ever former champions edition.

But before that, it’s the “Sal ‘The Voice’ Valentinetti Holiday Concert,” 8 p.m. Dec. 1, Miller Symphony Hall, Allentown.

Valentinetti lends his golden tones to a holiday concert of “ramped-up” Christmas songs like “Christmas Presents,” “Cool Yule,” “I’ll Be Home for Christmas” and “Most Wonderful Time of the Year,” paired with crooner classics such as “My Way” and “Come Fly With Me,” for which he is best-known.

“I never knew I could dream this big,” Valentinetti says.

As a boy, Valentinetti was introduced to the classic crooner sounds of Dean Martin, Tony Bennett and Frank Sinatra by his Italian-American grandmother.

In school, rather than sing, he played brass instruments in the band. His high school teacher urged him to take voice lessons after hearing him sing.

“I always had a passion for music,” Valentinetti says.

In 2016, the then 20-year-old college student was encouraged by his family to audition for “America’s Got Talent.”

He was hesitant but a bet with his Uncle Joe that he would give his nephew his Range Rover if he went to Hollywood changed his mind, Valentinetti says.

With his cousin Tommy in tow for moral support, Valentinetti waited in a long line to audition for the show in New York City.

When it was finally his turn, Valentinetti belted out the Frank Sinatra hit, “My Way.”

He not only got a standing ovation from the audience, but supermodel judge Heidi Klum pressed the “Golden Buzzer,” which meant he could go directly to the live show in Hollywood.

The video of his audition went viral, racking up more than 100 million views on YouTube.

“It’s so great that I got to perform the music my grandmother gave to me for thousands and thousands of people,” Valentinetti says in a phone interview.

He made it to the Top Five on “America’s Got Talent” and got to perform a duet of “Santa Baby” with Klum.

“It was a fantastic experience,” Valentinetti says. “Especially the exposure I got. As soon as I got home, there were emails and phone calls to perform. It was bigger than I ever could have imagined.”

Since then, Valentinetti has been touring the country and performing everywhere from intimate jazz clubs to Madison Square Garden. He works closely with various charities by hosting food drives at his shows and donating portions of his ticket sales to charities.

Valentinetti released his debut EP, “The Voice,” and an original holiday single, “When Christmas Comes to Town,” in 2017. In summer 2018, he released a second self-titled EP.

He says his Allentown concert will be an upbeat combination of American Songbook classics and Christmas songs.

“Christmas music makes people happy,” he notes.

Valentinetti says his concerts are like “you’re coming over to my house so I can sing to you and tell you stories.

“The only thing formal about my shows is my tuxedo,” he adds.

He promises to stay at Miller Symphony Hall until every last fan who wants to meet him, talk with him and take a photo is attended to.

He is looking forward to returning to NBC to compete on “America’s Got Talent: Champions,” which premieres 8 p.m. Jan. 7.

“It includes 50 of the audience’s favorite acts from all over the world to decide who’s the champion of champions,” he says.

“It has been really cool to check in with everyone.”

Sal “The Voice” Valentinetti Holiday Concert, 8 p.m. Dec. 1, Miller Symphony Hall, Allentown. Tickets: Miller Symphony Hall box office, 23 N. Sixth St., Allentown; allentownsymphony.org; 610-432-6715