Michael Bublé says his family was shocked when they heard his singing voice for the first time.

The “Sway” singer recalled the moment while speaking with Willie Geist for the Oct. 26 episode of Sunday Sitdown. Bublé said one Christmas Eve when he was 13 years old, he was sitting in the back seat of his family’s car driving back from his grandparents’ house.

“We were singing, I think it was ‘I’m dreaming of a white Christmas/ with every Christmas card I write.’ And then all of a sudden I went, ‘May your days be merry and bright.’ And it was, you know, the whole car going, ‘What the hell?’” he said with a laugh.

Bublé then started to take singing more seriously. While singing at a wedding in 2000, he was discovered by record producer David Foster, who signed him.

Bublé found success with his debut studio album, “Michael Bublé,” which he released in 2003. The album featured hits like “Sway,” “How Can You Mend a Broken Heart” and “Kissing a Fool.”

“My big hit songs were me sitting on a piano,” he said. “What would take an average piano player seconds, and it takes me hours to plunk out, ‘I don’t know why you think that you could hold me.’”

On Spotify he now has over 16 million monthly listeners. One notable fan? Baseball star Shohei Ohtani.

The Los Angeles Dodgers star, who’s currently facing the Toronto Blue Jays with his team in the World Series, has used Bublé’s “Feeling Good” as his walk-out song.

Bublé explained that it was Ohtani’s wife who told her husband that he should walk onto the field to that song.

“The coach of the Dodgers was nice enough to introduce me to Shohei. And I said to him, ‘Why did you choose my song?’ And very quickly, he just turned to his wife, and it was his wife that chose,” Bublé laughed. “I’ll take it.”

The five-time Grammy winner is gearing up for the next season in his life. While working as a coach on “The Voice,” he says he’ll be releasing new music soon, just in time for the holiday season.

Bublé admits he used to not want to be known for just his holiday songs. Then his son Noah was diagnosed with cancer at age 3. In addition to Noah, who is now 12 and in remission, Bublé shares children Elias, Vida and Cielo with wife Luisana Lopilato.

“I don’t know why, but I had the clearest epiphany that day. And I remember thinking, ‘Why did I ever worry about anything else?’” Bublé said. “And from that day on, I never felt the same about it again.”