Imagine if Billy Joel had joined Deep Purple instead of writing " Piano Man ." In a sense, that's what happened when he formed his ill-fated heavy metal band Attila in 1969.

Piano Man Billy Joel opened up about falling for his best friend's wife in a new documentary, "Billy Joel: And So It Goes," premiering July 18.

Billy Joel reveals that he twice attempted suicide — sparked by his affair with a band mate’s wife — in his new HBO documentary And So It Goes, and that one of the attempts left him in a coma.

Five-time Grammy winner Billy Joel is a four-time husband. The legendary singer-songwriter, who’s currently married to Alexis Roderick Joel, said “I do” to three other women before he wed his final match in 2015.

And So It Goes” provides a window into the rocker’s creative process and personal life. The two-part film features more than 100 of Joel’s songs, interviews with Joel, his family and friends, and some of the biggest names in music,