Need visual images to support your research? Use ARTstor (U of I community only, library subscription resource).
ARTstor Resources in Music History http://www.artstor.org/using-artstor/u-pdf/inter-music-history.pdf
ARTstor Resources in Theatre and Dance http://www.artstor.org/using-artstor/u-pdf/inter-theater-dance.pdf
What is ARTstor you ask?
"ARTstor is a digital library of nearly one million images in the areas of art, architecture, the humanities, and social sciences with a set of tools to view, present, and manage images for research and pedagogical purposes."