Singer-songwriter Charles – who penned hits such as 'Walking to New Orleans' and 'See You Later Alligator' – passed away at his home in Abbeville, Louisiana, at the age of 71 and while the cause of his death remains unknown, he suffered from diabetes and was in remission from kidney cancer.
His publicist Karen Johnson said: "He is a classic American songwriter. His songs are real American songs."
His long-time friend and music collaborator Dr. John said of Charles:
"We were very close for 40, 50 years. We started writing stuff together in the 70s. He was very easy to work with and a special guy."
Charles and Dr. John had just finished an album together, entitled 'Timeless', and it will still be released next month.
In 2003, Charles and his manager Jim Bateman gathered recordings spanning 20 years for 'Last Train to Memphis'.
Bateman said Charles – who is survived by four sons - had a "spiritual" approach to his music.
Bateman added: "He always said he didn't write songs, they came through him. I wouldn't necessarily call it religious, but spiritual."