When researching performers and choreographers, it is usually very helpful to locate film of the person's work. You can search the Knox Library catalog for film by limiting the format type to: 
For more information about searching the Knox Library catalog, see the Library Films tab.
You may also wish to check:
WorldCat searches for films owned by libraries accross the country, and you can request them through the ILLiad service. Limit WorldCat search to 
"visual materials" (i.e. films). Borrowing films can be difficult, especially if it is rare and/or only a few libraries own it. Loan times are also usually shorter. Please contact Anne Giffey (agiffey@knox.edu) for additional assistance in locating films.
Additionally, you will want to search YouTube, GoogleVideo and other online video search engines for clips of performances.
For additional ideas for finding visuals (photos, etc.), see the Find Images tab of this Research Guide.