Schomburg Center for Research in Black Studies; lots of great video interviews with playwrights and artists. This link will take you to the Research Guide, African American Theater resources, created by Schomburg Center. The author links to several recent conversations, Theater Talks.
These resources are all FULL TEXT, and great places to start your research. NOTE: Encyclopedias and biographies are great ways to get started, but not considered as Scholarly or Academic sources.