Christie Brinkley is showing support for her ex-husband Billy Joel following news of his recent brain diagnosis. The supermodel, who shares daughter Alexa Ray with the legendary singer, posted a video on Instagram Saturday -- just one day after Joel revealed he had been diagnosed with normal pressure hydrocephalus.

American singer, song-writer and piano man, Billy Joel has canceled all his upcoming concerts across England and North America after being diagnosed with a rare brain disorder.

Music legend Billy Joel, beloved for his timeless hits like "Piano Man" and "Uptown Girl," has recently announced the difficult decision to cancel all his upcoming concerts, including dates across the U.