NEW YORK -- Lady Gaga urged people weathering the coronavirus pandemic to find a way to smile through the pain, while Stevie Wonder encouraged viewers to lean on one another as the superstars kicked off Saturday's all-star event aimed at fighting the coronavirus and celebrating health care workers on the front lines.

The two-hour TV special “One World: Together At Home,” curated by Gaga, was the second part of an eight-hour event supporting the World Health Organization alongside advocacy organization Global Citizen.

“I care so much about the medical workers that are putting their lives at risk for us,” said Gaga, who performed Nat King Cole's version of the song “Smile.”

Wonder performed “Lean On Me” by Bill Withers - who died on March 30 - while playing piano. He told viewers: “During hardships like this we have to lean on each other for help.”

Paul McCartney sang the Beatles' “Lady Madonna” and talked about the work his mother did as a nurse, while photos of health care workers were shown on the screen.

“One World: Together At Home,” airing simultaneously on ABC, NBC, CBS, iHeartMedia and Bell Media networks, is being hosted by Stephen Colbert, Jimmy Fallon and Jimmy Kimmel. It featured stars appearing in intimate settings, beamed virtually to the world.

Colbert told viewers to “take out their wallets and put them away.” Kimmel added that over $50 million had already been raised to help those during the worldly crisis.

Earlier in the day, a six-hour streaming event featuring Andra Day, Niall Horan, Kesha, Matthew McConaughey, Jack Black, Heidi Klum and Jason Segel aired on digital platforms as part of the “One World: Together At Home” event.

“It's Kesha from quarantine day 500. I miss my fans so much,” Kesha said, sitting in front of her fireplace as her cat made noises in the background. “I know that there's so many people working and not sleeping and sacrificing so much to help figure this out for everyone and I just think the vulnerability of us all as human beings right now is really showing a really beautiful side to humanity.”

After thanking those working on the front lines, she said: “I'm going to do the main thing I know how to do, which is play some music and hopefully this will just brighten your day, maybe just a little bit. That's my goal.”

The event will also include performances and appearances by The Rolling Stones, Taylor Swift, Oprah Winfrey, Billie Eilish, Jennifer Lopez, David and Victoria Beckham, Alicia Keys, Ellen DeGeneres, Pharrell Williams, Eddie Vedder, Kerry Washington, Celine Dion, Lizzo, J Balvin and Andrea Bocelli.

World renowned pianist Lang Lang, country singer Maren Morris, rock performer Hozier, British star Rita Ora and Emirati singer Hussain Al Jassmi also performed during the early part of the special, which included videos focused on health care workers on the front lines fighting the spreading coronavirus. It also aired a package of people getting married - some in front of their homes, others inside - during the pandemic.

⭕️ We’re LIVE! @FallonTonight, @JimmyKimmelLive, and @StephenAtHome are kicking off One World: #TogetherAtHome in support of the @WHO and health care workers on the frontlines of the COVID-19 pandemic. Turn up the volume, get cozy, and tune in NOW: https://t.co/QMSMOngS2h pic.twitter.com/KkVkZOl7lu — Global Citizen (@GlblCtzn) April 19, 2020

Stevie Wonder performing “Lean On Me” as a tribute is a joy to watch as well!#TogetherAtHome pic.twitter.com/rGJXd5Ppon — Mcsuper- Team Scorbunny ⚔️ (@Macusian12345) April 19, 2020