What are Duke Ellington’s best-known works?

Often collaborating with his longtime composing-arranging partner Billy Strayhorn, Duke Ellington was responsible for big-band jazz classics such as “Take the ‘A’ Train” (written by Strayhorn), “Mood Indigo,” “Echoes of Harlem,” “Concerto for Cootie,” “Cotton Tail,” and “Ko-Ko” as well as popular songs such as “Sophisticated Lady” and “Prelude to a Kiss.”