Lovebirds Christie Brinkley and Billy Joel called the whole thing off seven years ago

It was an unusual pairing to begin with. She was the leggy California-bred swimsuit model, he the bug-eyed Long Island singer-songwriter four years her senior and about three inches her junior.

But when Christie Brinkley, 40, and Billy Joel, 44, announced an ”amicable separation” on April 13, 1994, after nine years of marriage, many were still surprised.

Joel’s latest album, River of Dreams, had gone quadruple platinum, and Brinkley, a former art student, had painted the cover. Earlier that month, only weeks before the separation announcement, the Grammy-winning singer had postponed a concert to rush to his wife’s side after she survived a heli-skiing accident in Telluride, Colo. (Among the survivors were real estate developer Rick Taubman, whom Brinkley would wed eight months later; a son, Jack Paris, would follow.)

Although there were whispers that Joel’s frequent touring put a strain on the marriage, reasons for the breakup were never made public. But the Uptown Girl did give an inkling later that year: ”Just because people can express themselves through their art doesn’t mean they are great communicators in person.” The couple was granted dissolution of the marriage in August of 1994.

The relationship started out on a beautiful note — the two met in 1983 on the island paradise of St. Barts while Joel was — what else? — doodling on a hotel piano. The singer introduced himself, but Brinkley reportedly said she couldn’t take anyone named Billy seriously and called him Joe — a nickname that stuck. Both were nursing wounded hearts: he from a divorce from first wife and former manager Elizabeth Weber, she from her breakup with longtime boyfriend, race-car driver Olivier Chandon.

They married two years later on a yacht on the Hudson River, and daughter Alexa Ray was born in December 1985. Throughout the years, they made their home in the Long Island hamlet of Amagansett, and Brinkley sometimes accompanied the singer on tour (most memorably during 1987’s stop in the post-Chernobyl Soviet Union, where she traveled with a Geiger counter).

Today, Joel and Brinkley (who lives with her three children — Alexa, Jack Paris, and her youngest, Sailor Lee, with her fourth and current husband, architect Peter Cook — in Bridgehampton, N.Y.) remain friendly: This August 18, she is producing ”An Evening of Questions and Answers and a Little Music,” a benefit class with Joel for the STAR Foundation (Standing for Truth About Radiation), whose aim is to shut down nuclear power plants. Not bad for two people who endured such a romantic meltdown.