Billy Joel’s ex-wife Christie Brinkley penned a heartwarming message to the Grammy-winning singer after it was revealed he is battling a rare brain disorder.

“Dear Billy, The whole Brinkley gang is sending you lots of love and good wishes for a full and speedy recovery,” the model, 71, began in a post on Instagram Saturday.

Brinkley then shared she had been looking for “cute photos” of Joel and their daughter, Alexa Ray Joel, but she came across clips from one of his concerts instead. The videos featured her other daughter, Sailor Brinkley Cook, whom she shares with her second husband, Peter Cook.

Sailor, 26, is seen in the footage singing Billy’s “You May Be Right” backstage with him before a show. She and Christie then appeared to have a blast as Joel sang hits like “The Longest Time,” “Vienna,” “We Didn’t Start the Fire” and others in front of the audience.

Christie said of the montage she shared, “It made me laugh ..but it also reminded me of all the joy you create, and all the sensational sing a longs you’ve lead… you turn an arena of strangers into a living room full of friends as we all sway in unison.”

“I’m sure I’m speaking for everyone in that room when I say please take good care of yourself, we all want you back in that white hot spotlight,you’re OUR piano man,” she added, sending her well-wishes.

“And we’re always in the mood for your melodies. And we all hope you’re feeling alright! We Love You, the kids, me and a whole bunch of full arenas!”

Christie was married to Billy from 1985 to 1994, and welcomed their only daughter during that time.

In her memoir “Uptown Girl,” which was named after the 1983 hit song her ex famously wrote about her, the cover girl shared that she left Billy because his drinking would cause him to go missing for days at a time.

However, Christie reflected in an interview with Page Six, “I do think that we were probably really soulmates, it was an amazing time of my life. I had so much fun.”

Since their split, the exes continued to see each other when the singer would swing by to visit Alexa, 39.

Billy, 76, announced last week he was diagnosed with normal pressure hydrocephalus (NPH), a condition in which cerebrospinal fluid builds up in the skull and presses on the brain, per the Cleveland Clinic.

He said via Instagram that his health issues had been “exacerbated by recent concert performances, leading to problems with hearing, vision and balance,” and therefore he had to cancel remaining shows.

The “Honesty” singer said he doing physical therapy to help him recover from the illness.