Billy Joel serenades ex-wife Christie Brinkley with "Uptown Girl" at Madison Square Garden

Former couple remains on good terms after 1994 divorce

Brinkley was in the audience at Joel's sold-out show

Musician Billy Joel and supermodel Christie Brinkley have remained on good terms in the years after their divorce. The former couple tied the knot in March 1985 and welcomed daughter Alexa that December. They divorced in 1994, but have remained close friends.

On Friday, Brinkley attended Joel's sold-out show at Madison Square Garden. During the show, Joel serenaded his ex-wife with his hit song "Uptown Girl." Brinkley was visibly moved by the gesture, and she was seen singing along and dancing in her seat.

Joel has been married twice since his divorce from Brinkley. He was married to Katie Lee from 2004 to 2009, and he is currently married to Alexis Roderick.