At one point, [Billy] said to me, 'You going deep?' And I said, ‘Yeah, and you know you’re going to go deep too,'" the film’s co-director Susan Lacy says.

When it comes to Billy Joel’s music, it’s still Bach and roll to him. In an exclusive preview clip from the new HBO documentary “Billy Joel: And So It Goes” that aired July 18 on TODAY, the "Piano Man" explains how classical music shaped the songs he has made during his decadeslong career.

Steve Cohen, who is executive producing the new documentary "Billy Joel: And So it Goes," said that his fingers are crossed that the 76-year-old will perform again after his brain disorder diagnosis.

Alexa Ray Joel watched the new documentary about her father, 'Billy Joel: And So It Goes,' with mom Christie Brinkley. The film premieres in two parts on July 18 and July 25, on HBO Max.

He didn’t see the film until it was finished, so he stuck by that, and we took that as permission to tell the real story about Billy Joel.”

Directors Susan Lacy and Jessica Levin join Morning Joe to discuss the new two-part HBO documentary film 'Billy Joel: And So It Goes'.