These days, Harry Connick Jr is well known as a Grammy and Emmy Award-winning musician, singer, composer, actor, and a legendary live performer.

But the multi-platinum best-selling artist was also once a young boy whose mother believed in him.

Their time with each other was tragically cut short when Anita-Francis Livingston Connick, who was affectionately known as Babe, died when Connick Jr was just 13.

When his mother was diagnosed with ovarian cancer, Connick Jr, who was then a young piano prodigy, tried to immediately make her wish — that he would one day perform at Carnegie Hall — come true, so that she could be there in the audience.

"I called Carnegie Hall to see if I could play there," Connick Jr told ABC News.

"And it was just the box office, so there was nothing they could do."

So, Connick Jr waited.

He waited a long, long time.

Earlier this year, on May 22 and 23, Connick Jr made his Carnegie Hall debut.

The earlier date would have been his mother's 100th birthday.

It meant so much to Connick Jr to fulfil his mother's dream in this way that he rehearsed off site, so that the moment he walked onto the stage would be his first time performing there.

"It was probably the most unusual performance I've ever done only because it's been a place that I've wanted to play for almost 50 years," Connick Jr said.

"I first knew about it because my mum had a vision for me to play there.

"She always wanted me to perform there since I was a little kid.

"I had never been inside that room because I wanted to wait for a special occasion.

"And then on May 22, I walked out, never having been in there, and I walked out on the stage for the first time and played and it was just magical."

The performance is now an album available on streaming services, CD and vinyl, and he's written a book with the same title.

Connick Jr wanted Babe: Elaboratio A Tribute to My Mother to be written as he remembers her.

It isn't a biography, he says, it's a tribute.

"It was important for me to speak from only my perspective because that's what the music was," Connick Jr said.

"It wasn't about other people's memories.

"It was all about an elaboration based on the memories that I had.

"Otherwise, it wouldn't have been as personal.

"I could have talked to my sister and compared stories with her, but it wouldn't have been my memory.

"I think there's something really special about how we all experience things and remember things.

"And it's so interesting how different people have different perspectives of things.

"So, if I wanted this to be my perspective, then I had to keep it within the confines of my own memory."

His mother was a trailblazing judge in New Orleans, and while her career milestones are categorically impressive, it's clear she also applied her determination and wisdom in motherhood.

In the book, Connick Jr paints a scene in which he packs his bags as a young boy with the aim of running away from home.

His mother, too, packs her bags, indicating she was going with him.

It's a beautiful, tender moment between mother and son that made Connick Jr realise he didn't want to run away after all.

"She was a great believer in the discovery process," Connick Jr said.

"And so, if there was an opportunity for me to learn something, experientially as opposed to her explaining it to me, then she would take advantage of that.

"So, when I was wanting to run away, she went and got her suitcase and said, 'let's go'.

"And it put me in a position of realising that I really didn't want to run away, and I was just upset about something.

"And she allowed me to figure that out for myself.

"And that's who she was.

"She was a big believer in that sort of way of raising kids."

Babe: Elaboratio is out now.