Watch: Coldplay star Chris Martin in 'moving' tribute to George Michael
Singer Chris Martin performed an "emotional" tribute to George Michael during a surprise appearance at a homeless shelter.
The Coldplay frontman offered his own rendition of hit Wham! song Last Christmas at the Crisis shelter in Ladbroke Grove, west London, days after the pop star died.
Michael (53) was found dead at his home in Oxfordshire, on Christmas Day.
Martin played guitar on the famed festive tune while shelter guest Kevin, dubbed "king of karaoke", sang.
Shelter volunteer Nish Manek (29) said the performance was "moving" and described Martin as "humble".
"He was serving cups of tea to guests for a while and then started performing with them. He was playing guitar and let them sing for most of it," she said.
"They all thought it was really cool and enjoyed singing with him."
Trainee GP Ms Manek said Martin's choice of song was particularly moving because some people were concerned about the post-Christmas period.
"It was a couple of days after Christmas Day, so some of the guests were worried about going back to their lives. It was quite emotional," she said.
Confirmation of Michael's death was met with tales of the singer's benevolence and charity work.
The star kept many of his donations secret as he was "determined not to make his generosity public", according to Childline president Esther Rantzen.