While most of America was celebrating the 239th anniversary of its independence, Billy Joel was surrendering his. Joel, 66, married fiancée Alexis Roderick, 33, at his estate in Long Island. As People reported, no less a personage than New York Gov. Andrew Cuomo (D) presided over the ceremony of the couple, who is expecting a child.

Joel and Roderick “surprised guests at their annual July 4th party by exchanging vows in front of their family and close friends,” Joel’s spokesman told People.

This was news of the “man bites dog” variety. Roderick is Joel’s fourth wife; he was previously married to Elizabeth Weber (1973-1982), Christie Brinkley (1985-1994) and Katie Lee (2004-2010). What’s less known is that, though Joel’s marriages may have cost him much filthy lucre — the singer has said he’s worth more than $160 million — these relationships (and others) have paid dividends in other ways: raw material for songs, some of them huge hits. Because, as it turns out, lyrics as good as “she’ll take what you give her as long as it’s free” don’t come free.

Here’s a look back at the love affairs behind the music:

“The Piano Man”

Joel’s portrait of drinkers down on their luck, released in 1973, wasn’t that different from his life as he sought fame and fortune in the music business. Joel made a failed album, stole his bandmate’s wife and attempted suicide after facing hard times.

“It was 1970,” Joel told biographer Fred Schruers. “I’d reached the age of twenty-one and still had no money. I had no place to live … crashing at my mom’s place again, which is abject failure, when you have to go back to your parents’ house. To avoid that I’d been roaming about like a homeless person – crashing on friends’ couches, sometimes in a car I’d find unlocked, in the warmth of a Laundromat, back and forth in the subways of Queens, even in the woods.”

Joel, of course, recovered, marrying Weber, his first wife and future manager. She is the “waitress practicing politics” of “Piano Man.”

“These were the days of, if not wine and roses, then rye and high hopes for us,” Joel said.

“She’s Only a Woman”/”Just the Way You Are” 

Joel wrote these ballads about a femme fatale for Weber, calling “She’s Only a Woman” a “tribute to Elizabeth.” Some said the song, and the similarly themed “Just the Way You Are,” were misogynistic; the singer denied it.

“My take was ‘She can ruin your faith with her casual lies/and she only reveals what she wants you to see’ — all second person — but then it comes back to me: ‘She’s always a woman to me,’” Joel said. “Yes, she can be difficult, she can be confounding, she can be impossible, but she’s obviously a better businessperson than you are.”

Joel may have regretted his observation. Weber’s reaction upon first hearing “Just the Way You Are”: “Do I get the publishing, too?” Joel later sued Weber’s brother, whom she brought into the Joel organization, for $90 million.

“And So It Goes”

This lesser-known tune is about one of Joel’s lesser-known relationships — with supermodel Elle Macpherson.

“I remember somebody got a shot of us walking down a beach at Coney Island,” Joel told Schruers. “… Elle was so tall that I looked like Bubbles the Chimp next to her, and I realized this was just not going to work.”

Joel funneled his insecurities into “And So It Goes” after Macpherson landed her first cover: “And so it goes/And so will you soon I suppose.”

“Uptown Girl”

Many assume this song is about Christie Brinkley — after all, she’s in the video. It’s actually about Macpherson and Brinkley — or was, until Joel settled down with the latter and changed the original title, “Uptown Girls,” to the singular.

“I had gotten divorced and I started dating these different women,” Joel said in an interview posted to his Web site. “I was going out with models. I was a rock star — a single guy who was a rock star. I was amazed at my good fortune at the time. … I started writing songs about these experiences. I kind of felt like a teenager all over again.”

Even the format of the song — a Frankie Valli tribute Joel has said is “the inverse of ‘Rag Doll,’ in which the singer is a rich guy, she the poor girl” — was a throwback to his youth. But it’s a throwback that resonates decades later — Joel sang it to Brinkley, with whom he remains quite visibly friends, at Madison Square Garden last year.