Sir Tom Jones and Little Mix have paid tribute to NHS workers during a British version of the star-studded One World: Together At Home virtual concert.
A host of big names performed from home on the US broadcast earlier, before more British stars were added to the line-up for a UK edition on BBC One.
The event aimed to celebrate healthcare workers during the Covid-19 pandemic.
Little Mix singer Perrie Edwards said NHS staff and other key workers "all deserve such a huge thank you".
The girl group were among the UK acts who took part in the British version of the concert on Sunday, along with Rag 'N' Bone Man, George the Poet and The Kingdom Choir.
It was presented by Dermot O'Leary, Clara Amfo and Claudia Winkleman - who, unlike their home-based US counterparts, hosted together in a studio.
Sir Paul McCartney, Sir Elton John and the Rolling Stones all filmed themselves singing in their own lavish homes, and all appeared in the main concert on US TV on Saturday and the UK version.
Lady Gaga, Stevie Wonder, Billie Eilish and Taylor Swift were among the US stars in both. Ellie Goulding, Jess Glynne, Michael Buble, Jennifer Lopez, Sam Smith and John Legend also appeared.
'Stick with it'
Sir Tom performed The Glory of Love and told viewers he was isolated for two years when he had tuberculosis as a child.
"I thought that was bad then," the 79-year-old said. "But the National Health Service helped me then like they're helping all of us right now.
"So I would like to say thank you so much to the National Health for doing what they did for me then and what they're doing right now for everybody else and we have to do our best to stay home to help the National Health.
"We should stay home and follow orders and go along with what we're being told to do.
"Stick with it, be together and we'll survive."
Little Mix performed their hit Touch with all four members in different locations. Edwards said she hoped fans were "being positive during this weird, weird time".
She said: "I think we can all agree that the love that we feel for the NHS staff at this time and the key workers, doctors, nurses, carers, retail workers, postmen, waste collectors, the list goes on and on.
"You all deserve such a huge thank you and we appreciate you so, so, so much. Everybody please take care of yourselves, take care of your loved ones, stay home, save lives, protect the NHS."
Sir Paul called healthcare workers "the true heroes" of the crisis, and remembered his mother Mary, who was a nurse during World War Two.
"Let's tell our leaders that we need them to strengthen the healthcare systems all round the world so that a crisis like this never happens again," he said before launching into Lady Madonna.
Although the show was dubbed the "lockdown Live Aid", the stars weren't asking viewers to donate to charity.
Instead, Global Citizen, the organisation that put the show together with the World Health Organization (WHO) and Lady Gaga, said "world leaders, corporate partners and philanthropists" had pledged $127m (£100m) during Saturday's event to support health workers.
As well as raising funds and celebrating front-line staff, the broadcast gave viewers a glimpse into the homes of pop and rock superstars - from Taylor Swift's floral wallpaper to Sir Elton John's basketball hoop and US singer Charlie Puth's unmade bed.
Ooops I forgot to make my bed 🙃— Charlie Puth (@charlieputh) April 18, 2020
The Rolling Stones managed to play together from four separate locations - although drummer Charlie Watts did not appear to have a drum kit in his house.
Instead, he banged on flight cases and the arm of a sofa for their rendition of You Can't Always Get What You Want.