Ray Charles

The song “What’d I Say” was improvised one evening late in 1958
when Charles, his orchestra, and backup singers had played their
entire set list at a show and still had time left; the response from
many audiences was so enthusiastic that Charles announced to
his producer that he was going to record it.

For the rest of his career, Charles closed every concert with the
song. It was added to the National Recording Registry in 2002
and ranked at number 10 in Rolling Stone ‘​s "The 500 Greatest
Songs of All Time".