Bethpage’s Sal Valentinetti has got the world on a string. The crooner, 20, made his debut on NBC’s “America’s Got Talent” Tuesday night, when he stepped in front of judges Howie Mandel, Mel B, Heidi Klum and Simon Cowell.

Come Thursday, he was back at Cassariano Italian Eatery in Mineola, where he regularly sings for the dinner crowd.

“My phone’s been buzzing off my nightstand,” said Valentinetti, who attends St. John’s University and delivers pizzas for his cousin. “Twitter is blowing up, Instagram is blowing up, Facebook is blowing up. I’m elated, I’m overjoyed.”

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On Tuesday’s episode, he sang a moving rendition of “My Way” that garnered a standing ovation. He left the stage covered in confetti after Klum invoked a “Golden Buzzer” to send him straight to the competition’s quarterfinals. His YouTube video of the performance scored over a million hits in less than 48 hours.

Every other Thursday night, Valentinetti sings standards like “The Way You Look Tonight” and “I Left My Heart in San Francisco” while patrons enjoy entrees and cocktails.

“I caught him on ‘America’s Got Talent’ and it was the best thing I ever saw, so I had to come down,” said Mary Jane Piscitelli, 69, of East Meadow. “He does our kind of music – very enjoyable.”

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Even 16-year-old Kealee Hohmann of Oyster Bay can connect with Valentinetti’s old-school delivery.

“I just love him,” she said. “I like that he’s really fun and that he’s into his music.”

Valentinetti said his late grandmother was the one who developed his taste for the music of Frank Sinatra, Tony Bennett and Bobby Darin.

“When she passed away, the music is all I really had to remember her by,” said Valentinetti, who also competed on season 14 of “American Idol.” “It grew into singing in the shower. The music inspired me to try my talent out.”

The singer is in training for his next round of competition on “America’s Got Talent,” and said he’s lost 50 pounds since his audition by working with a trainer.

“I’m taking this very seriously,” Valentinetti said. “I want to entertain America for the rest of my life. This is my calling. I will prove to people that I want it more than anybody else on that stage.”