What is “incident light”?

Which of the following groups is most closely identified with soul jazz?

a) Dave Brubeck Quartet b) John Coltrane Classic Quartet c) Adderley Brothers Quintet d) Jazz Messengers

In researching the play Joe Turner's Come and Gone, the actors in the production:

A. Watched movies on slavery B. Looked at old photographs of Pittsburgh C. Traveled to Pittsburgh D. Traveled to the deep South