A small-statured man in a fine suit, hunched over and silhouetted against a smoky backdrop — trumpet to his mouth about to play a softly muted note that no one expected but perfectly fits the moment.

Cootie Williams, 77, a jazz trumpeter, was the last surviving member of the Duke Ellington Orchestra that played the Cotton Club in Harlem during the 1920s. Playing professionally for more than 50 ...