Sir Elton John praised the "incredible" gift that the late Princess Diana had to make everyone feel at ease.
The 'I'm Still Standing' hitmaker was close to the British royal before her untimely death in August 1997 and was amazed by the royal's ability to make everyone "feel that everything's gonna be all right".
He said: "She had that incredible ability - which [Harry] knd of inherited - to make people feel at ease and make them feel that everything's gonna be all right.
"I haven't experienced many people in my life who have that ability, but she could walk into a room of people and make them feel as if everything was great."
And Elton also praised Diana for raising awareness of HIV and AIDS and the treatments available.
Speaking in the 'Diana, Our Mother: Her Life and Legacy' documentary about the stigma surrounding the disease, he added: "It was considered to be a gay disease. For someone who was within the Royal Family and who was a woman, and who was straight, to have someone care from the other side, was an incredible gift."
It comes after the 70-year-old singer heaped praise on Prince Harry for continuing his late mother's charity work.
He said: "If his mother was alive, she'd still be doing the work she set out to be doing, and he's carrying it on in the best possible way."
And Elton thinks Diana would have been "so proud" of Harry for raising awareness of HIV.
He wrote on Instagram last year: "In 1991, Princess Diana moved a mountain by addressing the stigma surrounding people living with HIV/AIDS. She showed the world we could safely wrap our arms around AIDS patients, by shaking hands with a patient without gloves. We've made huge strides since then in the treatment of the disease.
"People now live long, happy lives with HIV, when the virus is effectively managed with anti-retrovirals. Despite this amazing progress, most people today are still frightened and stigmatised at the notion of taking an HIV test. Today in London, Prince Harry gave that stigma a knock on the head by showing the world how easy and simple it is to take an HIV test. Bravo Prince Harry! Your mother would be so proud of you."