You may recall our post from a while back about popular mashup artist Girl Talk, where we noted all the clearance and licensing hoops he'd have to jump through for his records to be 100 percent legal. Our takeaway? The current sample license clearance process is likely too time-consuming and cost-prohibitive for Girl Talk to make his art legit.

According to some press accounts, Girl Talk and his label, the aptly named Illegal Art, believe that his work is legal under the fair use principle — meaning, there's exceptions within US copyright law that could protect him from being liable for infringement.

So what, exactly, is fair use? It's a part of copyright law that recognizes that there are certain, limited conditions within which a copyrighted work can be used without requiring permission from rightsholders for "purposes such as criticism, comment, news reporting, teaching, scholarship, or research" without being considered unlawful. Whether Girl Talk's work falls into these categories is literally a matter for the courts: fair use is only applicable when a case for infringement is made — it's what law-type folks call an "affirmative defense." Girl Talk has yet to be sued for infringement, which means that his fair use claims are currently rocking in the realm of the theoretical.

Keep in mind that fair use isn't only about music — it's meant to apply to all copyrighted material, from print to photography to film. Yet there is not a fair use precedent in music (with the exception of limited personal use protections for consumers), which means that using other peoples material in your own creations — no matter how small a snippet — requires clearance from the copyright owner(s). And keep in mind that there are two copyrights in music — the sound recording copyright and the underlying composition — which makes things that much more complicated.

Over the years, a string of court decisions (including Cambell v. Acuff-Rose Music Inc. 510 U.S. 569 [1994], Newton v. Diamond 349 F.3d 591 [2003] and Bridgeport Music v. Dimension Films 410 F. 3d 792 [2005]) have impacted the scope of fair use in copyright. In the wake of these rulings, there are those who have argued that current fair use exceptions aren't enough to deal with the realities of our tech-driven, networked era. Some, in fact, suggest we need a legislative fix.

In an effort to realign fair use to accommodate contemporary behavior ? creative and consumptive ? the public interest organization Public Knowledge has recently released a proposal to amend Section 107 of the Copyright Act [PDF]. This is part of a series of recommendations aimed at addressing multiple aspects of copyright in the digital age. Public Knowledge?s first proposal would extend fair use to include:

1. incidental uses (uses that capture copyrighted material where the material is not the primary focus)

2. non-consumptive uses (where the use does not rely on the underlying creativity of the work)

3. personal, non-commercial uses (such as burning a CD for personal use or creating a YouTube video)

It's possible that these revisions could work for copyrighted works in movies and literature — like a documentary interview with a famous photo in the background, or a reprint of a book for the purpose of critiquing the font — but do they make sense for audio recordings? Fair use in music involves highly contextual legal analysis, and nowhere is this more evident than in digital sampling. The law is clear that you need a license to use any part of the sound recording, but you might not require a license if you use a minimal amount of the underlying composition, even if the portion can be clearly identified in the end product. Of course, the latter use would still have to be successfully tested in court as a defense against infringement before it was considered lawful.

So what about an artist like Girl Talk, who remixes upwards of 20 songs to create a single dancefloor anthem? Do Girl Talk's mashups qualify as "incidental" uses? Could they feasibly be considered non-commercial? Similarly, would a filmmaker still have to pay for an eight-second clip of a tune heard in a convenience store scene, or could they claim fair use because it?s not the "primary purpose" of the movie? Here, Public Knowledge's proposals are unclear, at least to us.

Copyright essentially calls for balance between respecting creator's rights (and their potential marketplace reward) and establishing a public domain where others are free to use and build upon existing work. The fair use proposals advanced by Public Knowledge are a good step in highlighting this balance while generating discussion about issues that impact an increasingly broad section of the public — even if they don't know it. Still, it's possible that a set of provisions that could work for some forms of expression may not provide sufficient guidance for more nuanced uses.

In other words, the Public Knowledge proposal is an excellent jumping off point for a more detailed — and necessary — discussion about how the use and re-use of existing creative works can be reconciled with the realities of today's digital environment. Workable solutions are notoriously difficult to achieve, but that doesn't mean we should stop kicking around ideas. Who knows, maybe we'll crack this Girl Talk riddle yet.