Who wants to participate in my third paper?

 Hi everyone, 

Going along with my semester-long quest to understand copyright law, I've decided to examine our own conceptions of "fair use" in copyright law. I want to open these questions to all of you on Serendip. Responses would be much appreciated!

According to the US Constitution, the purpose of copyright law is to “promote the Progress of Science and useful Arts, by securing for limited Times to Authors and Inventors the exclusive Right to their respective Writings and Discoveries” (Article I, Section 8). Over time, copyright protection has been extended to virtually all forms of the media, including musical works, computer software, and visual works. However, as copyright law encompassed more works the question of violation arose: what is copyright infringement and where is the line drawn between appropriate and inappropriate use of copyrighted works? To answer this question, the concept of ‘fair use’ was introduced. Fair use was supposed to grant a “privilege in others than the owner of a copyright to use the copyrighted material in a reasonable manner without . . . consent” (Duke University School of Law).Fair use was designed to encourage the dissemination of ideas through new and novel mediums. But what constitutes “fair” use and “unfair” use was never properly delineated and has remained subject to the interpretations of various courts. 

In light of this information, I ask:

Are audio tracks that use similar musical patterns “fair”? (cf. Soft Cell’s Tainted Love with pop singer, Rhianna’s, S.O.S)

Are unquoted passages in books “fair”? (cf. The Sand Child by Ben Jelloun and “The Wasteland” by T.S. Eliot)

Are films that feature elements (characters, plots, etc.) of other films “fair”? (cf. the Scary Movie series)

Are paradoies “fair”? 

Where do you think the line between “fair” and “unfair” use lies? Further, what do you think should be done to the current concept of “fair use” to make it more effective in achieving the goals of copyright law as stated by the Constitution?