Billie Eilish, Mariah Carey, Alicia Keys and Dave Grohl open their doors to the world for fundraiser

Billie Eilish, Mariah Carey, Alicia Keys and Dave Grohl opened their doors — literally — as the musicians performed from their homes for an hour-long benefit concert to raise money for those affected by the coronavirus crisis.

Keys kicked off the Sunday's event — which also honoured health professionals and first responders — singing her song Underdog from a piano in her home. She thanked those "risking their lives to keep us safe."

Carey, one of the last performers, sang Always Be My Baby from her home studio in New York, then told the audience she was going to put on gloves.

Elton John sang and also hosted the special that aired on Fox and iHeartMedia radio stations; he said he hoped "this entertainment will feed and fuel your soul."

The homebound setting wasn't a stretch for the home-schooled Eilish, who typically performs live alongside her brother-producer Finneas, who is either on guitar or piano. On Sunday, he strummed along as Eilish sang her No. 1 hit Bad Guy from their couch. The concert special came on the one-year anniversary of Eilish's Grammy-winning debut album When We All Fall Asleep, Where Do We Go? — which Finneas and Eilish produced and recorded from their home in Los Angeles.

Eilish told viewers she was happy she and her brother could provide "some sort of comfort during the crazy, crazy time."

The artists were filmed with cell phones, cameras and audio equipment in their homes. The event took place during the time slot that was to belong to the iHeartRadio Music Awards, which became part of a wave of public-event postponements and cancellations because of the pandemic.

Other performers included Tim McGraw, H.E.R. and Sam Smith, who sang How Do You Sleep in a cappella form. Dave Grohl sang My Hero from his studio in Hawaii, Green Day's Billie Joe Armstrong strummed his guitar to Boulevard of Broken Dreams, while Camila Cabello sang My Oh My from Miami with a guitar assist from beau Shawn Mendes.

The five members of the Backstreet Boys performed from separate locations to sing their classic hit, I Want It That Way. And Demi Lovato sang her emotional song Skyscraper while playing piano.

Lady Gaga, Lizzo, Melissa McCarthy, Ryan Seacrest, Ken Jeong and others made special appearances, thanking first responders and telling viewers to practice safe habits like hand-washing and staying home.

"I see a lot of inspiring stories of kindness around the world that are helping to calm everyone's nerves during this scary time. My heart goes out to people who have lost loved ones and also to people that are losing their jobs," said Gaga, who postponed the April 10 release of her album Chromatica, saying it's not the right time amid a global fight with the coronavirus.

"I just wanted to check in and make sure that you're finding the time to be kind to yourself and doing whatever you can to maintain your mental health."

My heart goes out to people who have lost loved ones and also to people that are losing their jobs.- Lady Gaga

Like Gaga, other artists have changed release dates on projects because of the virus, and artists have had to cancel or postpone live shows because of social-distancing mandates.

For most people, the new coronavirus causes mild or moderate symptoms, such as fever and cough that clear up in two to three weeks. For some, especially older adults and people with existing health problems, it can cause more severe illness, including pneumonia and death.

Viewers watching Sunday's concert special were asked to support two of the charitable organizations aiding victims and first responders during the pandemic: Feeding America and First Responders Children's Foundation.

Some police officers and health care professionals spoke in between performances, with one ICU nurse in tears as she told viewers about her emotional day treating victims carrying the virus.