"In United States copyright law, **fair use** is a doctrine that permits limited use of copyrighted material without acquiring permission from the rights holders. Examples of fair use include commentary, search engines, criticism, news reporting, research, teaching, library archiving and scholarship. It provides for the legal, unlicensed citation or incorporation of copyrighted material in another author's work under a four-factor balancing test." -Wikipedia

"mash-up: something created by combining elements from two or more sources: as
a : a piece of music created by digitally overlaying an instrumental track with a vocal track from a different recording
b : a movie or video having characters or situations from other sources c : a Web service or application that integrates data and functionalities from various online sources" -Merriam-Webster

"parody: a piece of writing, music, etc., that imitates the style of someone or something else in an amusing way" -Merriam-Webster

"public domain: works whose intellectual property rights have expired, been forfeited, or are inapplicable." -Wikipedia

"remix: a variant of an original recording (as of a song) made by rearranging or adding to the original" -Merriam-Webster

Tools and Resources:
10 Apps for Multimedia Remixing from Edshelf
Copyright and Fair Use for Educators extensive collection of resources from Edutopia, including a video playlist
Document the Fair-Use Reasoning Process pdf
Fair Use Evaluator by Michael Brewer & the ALA Office for Information Technology Policy
Public Domain Sherpa tool to determine whether a specific work is in the public domain
Public Service Announcement Rubric pdf by ReadWriteThink. Includes Fair Use component
Summaries of Fair Use Cases list compiled by Stanford University Libraries
Tool for Supporting the Fair Use Reasoning Process pdf by Kristin Hokanson & Renee Hobbs, Temple Media Education Lab

Videos and SlideShares:

A Fair(y) Use Tale

YouTube Copyright School

Copyright Education User Rights

Scary Poppins: An example of Fair Use/parody