Statutory exemptions were written into the copyright law to help certain groups, under certain conditions, to copy or display a work. Fair use is one such exemption. And one is Section 110 of the law, which offers exemptions of certain performances and displays in an educational environment. That is, if the material was obtained lawfully, the work can be used:
The above is similar to the TEACH Act, which expands on that act for distance learning purposes.
There are also library exemptions (strictly for library personnel to deal with).
There may be other exemptions which apply to you. Check the U.S. Copyright Office Web site.
NOTE: The above (both sections) may not be a complete list.