Conversation so far:
When did Duke Ellington die?
Duke Ellington died on May 24, 1974.
What was something significant that happened in Duke Ellington's last years?
In 1999, Duke Ellington was posthumously awarded a special Pulitzer Prize commemorating the centennial year of his birth, in recognition of his musical genius.
What recordings did Duke Ellington make?
Duke Ellington also recorded songs written by his bandsmen, for example Juan Tizol's Caravan, and Perdido, which brought a Spanish tinge to big band jazz.
Did Duke Ellington tour when he still had a band?
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 year was Duke Ellington's final performance?
Duke Ellington performed what is considered his final full concert in a ballroom at Northern Illinois University on March 20, 1974.

Question: Where was his final performance?
Self-contained rewrite: Where was Duke Ellington's final performance?