Throughout the past two years, AI-powered stem-splitting services have emerged online, allowing users to upload any audio file and access extracted, downloadable audio stems. A “stem” is an audio file that contains a mixture of a song’s similarly situated musical components. For example, if one records a mix of twenty harmonized vocal tracks, that recording constitutes a vocal stem. Stems’ primary purpose is to ease integrating or transferring their contents into either a larger project or a different work. Traditionally, only producers or engineers created and accessed stems. Even when stem sharing became commonplace, it was only for other industry insiders or those with licenses. But AI stem-splitting technology has transformed stem access. For the first time, anyone with internet access can obtain a stem through stem extraction software, which will likely push music production’s creative envelope into new realms. One inevitable consequence, however, is the question of copyright protection over stems extracted from copyrighted works.
Section 102 of Title 17 extends copyright protection not only over the stems’ original copyrighted audio source but also over that source’s components, such as the stems. Any modification of that work, such as extracting a stem and using it elsewhere, likely qualifies as a “derivative work” under Section 103. Importantly, Section 106 allows only copyright owners to authorize making derivative works. In light of this regime, what flexibility, if any, do artists have in using AI-extracted, copyrighted stems? Three considerations shed light on an answer: fair use, de minimis use, and the use of content recognition software coupled with licensing.
Codified under Section 107, the fair use defense provides a possible safeguard for would-be infringers. To establish this affirmative defense, a court would need to find the statute’s four factors sufficiently weigh toward “fair use.” Unfortunately, courts reach incongruous interpretations of what permissible fair use includes, rendering the defense a muddled construct for many artists. Squaring the four factors with stem usage, however, may offer guidance.
In the seminal music fair use case, Campbell v. Acuff-Rose Music, Inc., the Supreme Court emphasized that this first factor will likely weigh toward fair use when the work is “transformative.” The Court went so far as to note “the more transformative the new work, the less will be the significance of other factors . . . .” Thus, an artist fearing infringement should strive toward transforming the copyrighted material into something distinct, used for noncommercial purposes. In the absence of a bright-line rule from the Court, however, artists will still need to use reasonable judgment about what types of stem usage is “distinct.” For example, suppose Artist A extracts a strings stem from a copyrighted work and only uses two seconds of it within another work that comprises numerous other instruments and melodies. Meanwhile, Artist B extracts the same strings stem; however, Artist B uses the entire strings melody within their work and only adds percussion and minor counter-melodies. Artist A would likely be in a more favorable legal position than Artist B given A’s efforts to materially transform the copyrighted audio.
The commercial nature of copyrighted stem usage is also unclear. An artist may choose to work with stems for solely experimental purposes. For example, an artist who shares their work via Soundcloud or YouTube does not expect another person to use those platforms to directly purchase the work. With stems’ increasing public accessibility, many will simply want to experiment with a music tool that, until recently, has largely remained a foreign concept. If this issue reaches a court, the court would need to conduct an analysis set against the landscape of such heightened accessibility. An increase in this noncommercial, creative use may offer hope to artists in the future, but it is too soon to tell.
The second factor favors artists borrowing from copyrighted works with lower creative value. Unfortunately, music is typically found to be one of the most creative forms of copyrighted work. For example, a district court in UMG Recordings, Inc. v. MP3.Com, Inc. analyzing this second factor noted that the disputed material—copyrighted musical works—was “close to the core of intended copyright protection” and “far removed from the more factual or descriptive work more amenable to ‘fair use.’”
Though courts’ future inquiries into stem usage may differ from previous analyses of sample usage, the inquiry will likely change very little for this factor. Although a stem could potentially represent only a minute portion of the song, this factor’s inquiry focuses on the source of the stem, rather than the stem itself. Consequently, rarely will this factor work to a potentially infringing artist’s benefit, even if their stem usage is quite minor.
The third factor, however, may offer hope for such minor stem usage. Courts will undoubtedly reach differing interpretations about how minimal the copyrighted portion’s “amount” and “substantiality” must be for this factor to weigh toward fair use. A court will need to weigh numerous variables and how they intersect. For example, is an artist using a thirty-second loop of a vocal stem or a five-second loop? Does that vocal stem include the chorus of a song? What about any distinct lyrics? Just minor humming? These considerations are not entirely novel. Artists purporting to use copyrighted samples have long been able to argue—with little success—that their samples’ amount and substance pass muster under this factor. Yet, stems are not samples; in fact, they typically represent a considerably smaller portion of a work. Given just how recent and novel their public accessibility is, it remains unclear whether a court would treat stem use any differently under this factor than it has treated instances of sample use. Carefully using a minor portion of a vestigial stem to avoid a work’s core substance, therefore, could potentially facilitate a favorable outcome.
The fourth and final factor of fair use is “[u]ndoubtedly the single most important element.” This factor examines both the infringement’s effect on the potential market and “whether unrestricted and widespread conduct of the sort engaged in by the defendant . . . would result in a substantially adverse impact on the potential market for the original.”
In the sampling realm, this factor has tipped the scales before. For example, in Estate of Smith v. Cash Money Records, Inc., a district court found fair use when the defendants inserted a thirty-five-second “spoken-word criticism of non-jazz music” into a hip-hop track. In its analysis of this fourth factor, the court emphasized that “there [was] no evidence” that pointed to overlapping markets between the spoken jazz track and the hip-hop track. The court, noting this factor’s high probative value, then weighed this factor in the defendants’ favor.
In the stem realm, the novel nature of widespread public use means courts will need to determine both whether this factor should remain highly probative and how much deference to give stem users in analyzing market overlap. After all, an artist who incorporates a stem into a work intended for a twenty-five-person YouTube following likely affects the original work’s market differently than an artist who disseminates that work to millions of followers. This factor’s outcome will also rely on the stem’s source. Similar to sampling, if an artist uses a stem in a drastically different arena than the one for which the stem was created, this factor will weigh more toward fair use.
For example, suppose Artist A locates an insurance advertisement jingle. Artist A then extracts a stem from that advertisement audio and uses the stem in a new hip-hop track. The advertisement’s potential market is likely different from the hip-hop track’s potential market. Artist A’s work would likely have little impact, if any, on the advertisement’s market. Artist B, meanwhile, creates a hip-hop track but uses a stem from another hip-hop song produced twenty-five years ago. Though Artist B may believe the stem from the older hip-hop track no longer caters to the same hip-hop market to which Artist B is targeting, a court may be more inclined to find a material impact on the older track’s market: it would provide another way in which music listeners, particularly hip-hop listeners, could hear that older track. Nonetheless, it would remain up for a court to decide.
De Minimis Use
Artists might also be able to use extracted, copyrighted stems if such use is de minimis. The Ninth Circuit in Newton v. Diamond held de minimis use—“when the average audience would not recognize the appropriation”—is permissible. Yet, following the Newton decision, the Sixth Circuit in Bridgeport Music, Inc. v. Dimension Films foreclosed the possibility of de minimis copying. Similar to fair use analysis, it is difficult for an artist to determine whether the use of a stem in their work is de minimis under this standard.
Thus, an artist who loops only a small, relatively generic-sounding portion of a stem may find additional legal protection. But they might not. If they are in a jurisdiction that does not recognize de minimis use, or they use a stem in a way that extends beyond what a court considers de minimis in a de minimis jurisdiction, this avenue will be unavailable.
Content Recognition Software
Beyond legal defenses, a newer scheme of licensing deals coupled with content recognition software may offer protection for stem usage. For example, if a user on the content platform TikTok uploads content with copyrighted audio, TikTok’s content recognition software recognizes the audio, then pays the appropriate royalties to the audio’s copyright holder through preexisting licensing deals. Yet, because schemes like TikTok’s and stem usage are both relatively new, it remains unclear whether artists could find the same protection through individual stem use. Indeed, if an artist uses only a small part of a single stem, it may very well be impossible to detect the stem’s source; however, emerging technology may change this soon. Further, these licensing deals restrict such artists to sharing work only on particular platforms—notably, neither Soundcloud nor YouTube. Ultimately, this protection carries promising potential for expanded, authorized stem use. But perhaps not quite yet.
Matthew Danaher is a second-year law student at Northwestern Pritzker School of Law.