The Library's catalog, cataLION, can lead you to both print and electronic materials on contemporary theatre. Try searches like the ones below:
WorldCat is an international catalog of book materials and may provide another option for your resarch.
Use the dropdown menu to switch to subject and type the following:
You can add other words to your search like art or literature.
For items about a specific playwright, type in the name as a subject, e.g.,
Collection of fulltext online reference materials. Content includes dictionaries, encyclopedias, atlases, and subject-specific titles from art to accountancy, science to Shakespeare, and law to literature. Coverage varies by title.