Conversation so far:
What important event happened in Duke Ellington's early post years?
In 1951, Duke Ellington suffered a loss of personnel: Sonny Greer, Lawrence Brown and, most importantly, Johnny Hodges left to pursue other ventures, although only Greer was a permanent departee.
Why was Duke Ellington forced to disband?
The big band era appeared to have ended after the war, and Basie disbanded the group.
Did Duke Ellington tour at all?
Following an appearance at the Newport Jazz Festival, in July 1956, Duke Ellington and his orchestra enjoyed a major revival and embarked on world tours.
What did Duke Ellington's playlist include?
Duke Ellington's playlist include normally included jazz music.
What did people think about Duke Ellington's music?
Martin Williams said: Duke Ellington lived long enough to hear himself named among our best composers.“
Why did Duke Ellington's music appear to be outmoded?
During the 1950s, Duke Ellington's career was at a low point with his style being generally seen as outmoded, but his reputation did not suffer as badly as some artists.
Did Duke Ellington work with other composers?
In the early 1940s, Duke Ellington began a nearly thirty-year collaboration with composer-arranger-pianist Billy Strayhorn, whom he called his writing and arranging companion.
Were there any other noteworthy people Duke Ellington worked with?
Some of the jazz musicians who were members of Duke Ellington's orchestra, such as saxophonist Johnny Hodges, are considered to be among the best players in the idiom.

Question: What was the work?
Self-contained rewrite: What was the work Duke Ellington collaborated on?