Billy Joel's wife was "very unimpressed with the whole Billy Joel thing" when they first met

In the new HBO documentary series Billy Joel: And So It Goes, he explains: "I remember the first time I met Alexis, we went to my house, and I wanted to play the piano for her. It's a form of communication for me."

Billy assumed that Alexis would be wowed by his award-winning talents. However, she was unmoved when he played the piano for her.

Billy - who married Alexis in 2015 - said: "I'm playing that and she's completely unimpressed with it, totally. She couldn't care less what I'm playing and I'm thinking, 'Oh OK, this isn't working.'

"She was very unimpressed with the whole Billy Joel thing, which impressed me. Because I thought, 'OK, maybe she's just here because she likes me, not the Billy Joel guy.'"

The music star - who has daughters Della, nine, and Remy, seven, with Alexis - made a conscious effort to develop their relationship away from the spotlight.

He explained: "We had a couple years together before we had kids and he had completely stopped doing shows. We travelled everywhere. We did a motorcycle trip from Maine down to Long Island, we were on boats 24/7. We were in Europe. We had so much fun."

Meanwhile, Billy recently admitted that he was hesitant about committing to his HBO documentary.

The music icon revealed that he was reluctant to reflect on some of the "stupid stuff" he's done in the past.

He told People: "I've resisted this kind of thing for so long. I'm sick of talking about myself. Some of the stupid stuff I did, that's painful to talk about. (But) they asked me for some thematic guidance. I said, 'Just tell the truth.'"

Billy initially just wanted to get the documentary "over with" because he doesn't enjoy talking about himself.

The Uptown Girl hitmaker said: "My goal was to get it over with.

"When I do interviews, people just ask you about yourself and you get a little self-conscious about it eventually. It's almost embarrassing.

"When you're talking about your personal life detached from the material ... I suppose there's a little bit of wariness involved."