Tony Bennett lead a worldwide sing-along on Saturday afternoon of his classic ballad "I Left My Heart in San Francisco" to pay tribute to frontline workers in the fight against COVID-19.
People were encouraged to join in, from their porches, laptops, backyards, balconies and smartphones at noon Saturday.
San Francisco Chief of Protocol Charlotte Mailliard Shultz, who came up with the idea, said it would be "a morale boost and an opportunity to pay respect to all of our frontline workers and brave medical professionals."
Participants were encouraged to live-stream and record their performances on social media with the hashtag #SingOutSF.
"San Francisco has been in my heart for over 50 years," said Tony Bennett. "I am so proud and impressed with how the City by the Bay has continued to 'bend the curve' during the COVID-19 crisis and serve as an inspiration to the world of how together and alone we can make a difference."
At 11:55 a.m., churches and houses of worship played bells, and then the sing-along will begin at noon.
At 12:05 p.m., the San Francisco Fire Department ran sirens on engine trucks and ambulances in tribute to first responders.
No gatherings or official performances are planned. Anyone singing outside is reminded that wearing a mask is mandatory and should observe social distancing protocols, organizers said.