Music legend Billy Joel made a surprise return to the stage on Jan. 2, performing live for the first time since disclosing in May that he had been diagnosed with a rare brain condition.

According to People, the 76-year-old singer appeared unexpectedly at a village amphitheater in Wellington, Florida, where fans had gathered to watch a Billy Joel cover band during the town’s anniversary celebration. Unaware of what was coming, the audience erupted as Joel walked onstage with a cane, sat at the piano, and launched into a brief set.

“I wasn’t planning on working tonight,” Joel joked before performing “We Didn’t Start the Fire” and “Big Shot” alongside the tribute band.

The performance was made more personal as Joel’s two youngest daughters, Della, 10, and Remy, 8, joined him onstage, clapping and dancing as he played.

Joel previously revealed that he was undergoing treatment for normal pressure hydrocephalus (NPH), a condition caused by a buildup of cerebrospinal fluid in the brain. His team said earlier this year that recent performances had worsened symptoms affecting his hearing, vision, and balance, prompting doctors to advise him to pause touring and focus on recovery.

In an earlier interview cited by People, Joel reassured fans about his condition, saying he was “okay” and doing his best to manage and recover from the illness. NPH, while often mistaken for dementia, is considered treatable and sometimes reversible with proper medical care.