Billy Joel's daughter, Alexa Ray Joel, says her father "continues to regain his strength" amid his battle with a brain disorder

A statement posted on his Instagram read: "Billy Joel has announced that he will be cancelling all scheduled concerts following a recent diagnosis of Normal Pressure Hydrocephalus (NPH). This condition has been exacerbated by recent concert performances, leading to problems with hearing, vision and balance."

Billy is currently undergoing treatment and doctors have advised that performing would have an adverse affect on his health at this time.

The statement continued: "Under his doctor's instructions, Billy is undergoing physical therapy and has been advised to refrain from performing during this recovery period. Billy is thankful for the excellent care he is receiving and is fully committed to prioritising his health. He is grateful for the support from fans during this time and looks forward to the day when he can once again take the stage."

Billy added his own message to fans, saying: "I'm sincerely sorry to disappoint our audience, and thank you for understanding."

According to clevelandclinic.org: "Normal pressure hydrocephalus (NPH) is a condition that happens when cerebrospinal fluid builds up inside your skull and presses on your brain. This condition is most likely in people over 65. It's often treatable and sometimes even reversible."

Subsequently, Billy cancelled his tour, which included 17 dates in North America and England.

Alexa Ray - whose mother is 71-year-old model Christie Brinkley - has since provided an update on her father's progress.

The 39-year-old offspring of 'The Piano Man' captioned a painting of a father and daughter on Instagram: "SOUND UP. We love you and we got you, Pop!

"I just wanted to thank you all for the beautiful outpouring of love and support amid the recent news of My Father's health diagnosis," Alexa Ray, who Billy shares with ex Christie Brinkley, continued. "My Dad is the strongest and most resilient man I've ever known ... and he's entirely committed to making a full recovery with ongoing physical-therapy treatments as he continues to regain his strength.

"The genuine care, empathy, and concern from everyone means so much to him ... it means a lot to me, too."

She concluded her post by sharing the lyrics to Billy's morbid 1993 track, 'Lullabye (Goodnight, My Angel)', which he penned for Alexa Ray.

She added: "Someday We'll All Be Gone / But Lullabies Go On And On / They Never Die / That's How You And I Will Be.

"The music continues... All My Love, Alexa Ray."

The 'Uptown Girl' hitmaker also has Della, nine, and Remy, seven, with fourth wife Alexis Roderick.