Billy Joel and Alexis Roderick got married on Saturday evening.
The couple “surprised guests at their annual July 4th party by exchanging vows in front of their family and close friends,” the singer’s spokeswoman said in a statement to PEOPLE.
The intimate ceremony, which was held at Joel’s sprawling estate on Long Island, was presided over by New York Governor Andrew Cuomo, 57, a longtime friend.
The singer, 66, and Roderick, 33 – an accomplished equestrian and a former Morgan Stanley executive – have been together since 2009 and are expecting their first child, a little girl, this summer.
“Billy is thrilled to become a dad again,” a source told PEOPLE in April.
The music legend is currently on tour, with his next sold-out stop at Boston’s Fenway Park on July 16.