Dec. 12, 2008 -- Joseph Harry Fowler Connick Jr. seemed destined to perform from the time he was born on Sept. 11, 1967, in New Orleans. While both of his parents were lawyers, they also owned a record store and encouraged their young son's passion for music.
At age 3, Connick was already learning the piano, and by the time he was 10 he was performing with a jazz band.
"Growing up in New Orleans, especially when you're interested in music, you have the whole city from which to draw inspiration from," Connick told "Nightline," in an interview conducted at the Empire Hotel Rooftop in New York City. "You have the whole city from which to draw inspiration from. It was an amazing place to be."
Watch this story tonight on "Nightline" at 11:35 p.m. ET.
So it is no wonder that as a teenager, Connick could be seen playing the clubs in New Orleans' French Quarter while attending the New Orleans Center for the Creative Arts. By the time he was 19, Connick had released his first album for Columbia Records and relocated to New York City to continue his studies at New York's Hunter College and at the Manhattan School of Music.
But it was in 1989 when a young Harry Connick Jr. hit the mainstream music world by composing and singing several songs for Rob Reiner's film "When Harry Met Sally."
The film's soundtrack went multi-platinum, and Connick's musical style earned him comparisons to Frank Sinatra. Sinatra even praised Connick and referred to his protégé as "The Kid."
For the past 20 years, Connick has performed everything from big-band standards to New Orleans funk and jazz. And in time for the holidays, Connick is promoting his second Christmas album, "What a Night!" But who inspires Harry Connick Jr.'s music?
"I pretty much like any kind of music. In my opinion, there's good and bad in all the different genres of music," said Connick.
'Nobody Knows the Trouble I've Seen'
"Growing up in New Orleans, Louis Armstrong is the king," said Connick. "I mean, he is the guy that everybody wants to be."
Connick said Armstrong's famous song, "Nobody Knows the Trouble I've Seen," is inspiring because it shows how Armstrong overcame the adversity in his life.
"[Considering] what he had been through in his life, he had been the victim of racism, and many other issues of the time ... and you will not hear a greater trumpet song on recording," he said. "It's troubled and it's strained, and it was late in his life and it's wobbly and cracked sounding.
"It's one of those things where God put his hand on Louis Armstrong and said, 'OK, you are the one. So you handle the music for the rest of us,'" Connick said.
'On the Sunny Side of the Street'
Connick credits James Booker's song, "On the Sunny side of the Street" with drawing him to the piano.
"James Booker was a New Orleans piano player and singer," he said, "and the finest of all of them in my opinion. James Booker was so unique and so ingenious in the way he approached the piano ... and it's in that style that I tried to pattern what I was doing. 'On the Sunny Side of the Street' is probably the single most influential piano music for me."
'Death on Two Legs'
"Freddie Mercury is one of my biggest heroes of all times," said Connick, "not only for his musical talent but his lack of inhibitions."
In the 1975 song "Death on Two Legs," most of the guitar parts were initially played on piano by Mercury, but it was his voice that inspired Connick.
"The very simple little triads that Freddie Mercury plays in the introduction -- the way he sings it, he just had no limits in his own mind as to what he could do vocally," he said.
"It sounded as if it were effortless the way Freddie sang, like his vibrato would kind of kick in sometimes and sometimes it wouldn't," Connick said. "The way he played piano seemed completely spontaneous, and clearly it wasn't."
'Only the Lonely'
Connick considers the music legend Frank Sinatra "the best of all of the male singers."
"'Only the Lonely' is one of the great musical performances," he said. "The songwriting, the orchestrations, everything was perfect. As somebody who does that for a living, I can tell you it is extremely hard to do what he did, especially when you consider what came before him.
"I mean, I have a lot of information from which to draw," Connick said. "You know, he didn't -- and it's a great masterpiece."
"I had listened to George Jones, but I had never really ... gotten into him," said Connick. "And after I did, I was mesmerized. ... There's a song that he does called 'The Door' and it's incredible. I mean, I've listened to that song 1,000 times and I'm always hearing new things that he does.
"I mean, not to undermine his process, but it seems like there's almost no thought that goes into it," Connick said. "Yet clearly, there is."