Leon Russell died in his sleep at the age of 74 in Nashville, Tennessee.
The rock’n’roll hall of famer was best known for his “gospel-infused southern boogie piano rock, blues, and country music”, his website says.
Leon Russell played anonymously as a studio pianist in the 1960s before his breakthrough in the 1970s.
The singer was inducted into the Hall of Fame in 2011. Elton John has called him his “biggest influence as a piano player, a singer and a songwriter”.
Leon Russell’s had a relatively brief period of stardom in the 70s which was later revived in 2010 with the help of Elton John when the two collaborated on an album called The Union.
The record took third place in a list of 2010’s best albums by the Rolling Stones.
Over his career, Leon Russell recorded more than 35 albums and was best known for his A Song for You.
A Song for You was recorded and covered by the Carpenters, the Temptations, Neil Diamond, Ray Charles, Aretha Franklin and his good friend Willie Nelson.