In the experimental post 1960s eras some of the influential bassists included Charles Mingus ( 1922 -- 1979 ) and free jazz and post-bop bassist Charlie Haden ( 1937 - 2014 ) .
The experimental post 1960s eras saw the development of free jazz and jazz - rock fusion .
In the experimental post 1960s eras , which saw the development of free jazz and jazz - rock fusion , some of the influential bassists included Charles Mingus ( 1922 -- 1979 ) and free jazz and post-bop bassist Charlie Haden ( 1937 - 2014 ) .