The 48-year-old singer got her big break as one of the late King of Pop's backing singers and has praised his stage presence as "divine brilliance".
She said: "He gave me my first job in the business. My strongest memories of Michael are his performances and getting to be a fly on the wall every night. I got to watch him in his divine brilliance, do what he did the best. There'll never be anyone like him again".
She said: "Marvin Gaye was a big influence because he could write a beautifully sexy song and at the same time combine it with a lyric which was a comment about what was going on politically at the time."
The mother of two also spoke about her long working relationship with rocker Keith Richards - who features on her new album `100 Miles From Memphis'.
She added: "I've had a long relationship with Keith and Mick as well. They were such huge influences on me and since 1994 they've just been so generous to have us open a show for them or to have me sit in with them."