Darius Campbell Danesh sung to Phones 4U boss John Cauldwell's frail mother in one of his final performances, months before his tragic death.
The Pop Idol star's heartbroken family announced the singer had died last Thursday, after being found dead in his bed at his flat in Minnesota in America.
His cause of death is still be investigated.
Following his death, John shared one of Darius' last ever performances and revealed the singer had flown out to perform at his mother's funeral four months ago.
The Colourblind star paid a visit to John's bedbound elderly mother, who was his biggest fan, and sung Nessum Dorma to her.
The touching clip saw Darius reach over to take her hand, with John's mum visibly touched by the gesture.
She mouthed the lyrics as Darius' operatic voice filled the living room.
John captioned the video: ""REST IN PEACE, DARIUS.
"I am unbelievably shocked and devastated by the news of Darius Campbell Danesh’s premature death at the age of only 41.
"I was lucky to know Darius, who was one of my mother’s favourite singers. In the many years that Mum was housebound, Darius visited her several times to serenade her in her bedroom. Mum would join in while beaming ear to ear.
"When Mum passed away earlier this year, it meant the world to me and the family to have Darius sing at her memorial service, a spine-tingling rendition of Hallelujah. He flew back specially from America for it.
"That was only four months ago, and in less than two months, Darius was due to perform at my own 70th birthday party.
"I cannot believe that this vibrant young man is now gone. He always seemed the picture of good health and good cheer, amazingly kind and amazingly talented. A man with a huge heart.
"Watching these videos again of Darius with Mum brings tears to my eyes. If there’s an afterlife, I hope they can reunite for another duet.
"My deepest condolences to Darius’ family, friends and many fans.
"Rest in peace, @official_darius_campbell."
