The family of legendary singer Tony Bennett has revealed that the crooner was diagnosed with Alzheimer’s in 2016 and continues to fight the degenerative disease through the COVID-19 crisis.

“His memory, prior to the pandemic, was so much better,” Dr. Gayatri Devi recently told AARP (Devi was the physician who diagnosed Bennett years ago). “And he’s not alone. So many of my patients are negatively affected by the isolation, the inability to do the things that matter to them. For someone like Tony Bennett, the big high he gets from performing was very important.”

According to his wife Susan, the 94-year-old Bennett struggled in comprehending the nature of the disease, especially since he has remained physically spry in old age. “He would ask me, ‘What is Alzheimer’s?’ I would explain, but he wouldn’t get it,” she explained. “He’d tell me, ‘Susan, I feel fine.’ That’s all he could process — that physically he felt great. So, nothing changed in his life. Anything that did change, he wasn’t aware of.”

Many music fans may recall the 20-time Grammy winner’s signature croon, most notably on his award-winning version of “I Left My Heart in San Francisco.” In his rise to fame, he was famously considered a successor to Frank Sinatra and even marched with Dr. Martin Luther King.

“For my money, Tony Bennett is the best singer in the business,” Sinatra told Life Magazine in 1965. “He excites me when I watch him. He moves me. He’s the singer who gets across what the composer has in mind, and probably a little more.”

Younger music fans might recall Bennett’s deep friendship with Lady Gaga, which began with Bennett’s 2011 Duets II album and stretched through their 2014 duo album Cheek to Cheek and its ensuing, successful co-headlining tour.

After his diagnosis, Gaga and Bennett soldiered on, kicking off the initial recording sessions for their follow-up record at New York’s Electric Lady Studios.

Reads the AARP account of the duo’s time in the studio:

In raw documentary footage of the sessions, [Bennett] speaks rarely, and when he does his words are halting; at times, he seems lost and bewildered. Gaga, clearly aware of his condition, keeps her utterances short and simple (as is recommended by experts in the disease when talking to Alzheimer’s patients). “You sound so good, Tony,” she tells him at one point. “Thanks,” is his one-word response. She says that she thinks “all the time” about their 2015 tour. Tony looks at her wordlessly. “Wasn’t that fun every night?” she prompts him. “Yeah,” he says, uncertainly. The pain and sadness in Gaga’s face is clear at such moments — but never more so than in an extraordinarily moving sequence in which Tony (a man she calls “an incredible mentor, and friend, and father figure”) sings a solo passage of a love song. Gaga looks on, from behind her mic, her smile breaking into a quiver, her eyes brimming, before she puts her hands over her face and sobs.

Read the full article via AARP here.

Watch Bennett perform “I Left My Heart in San Francisco” in 1994 below: