Music copyright infringement cases are decided on two basic questions: does the plaintiff own a valid copyright, and did the defendant copy protected expression from it? Ownership usually turns on a Copyright Office registration. Copying is where the fight happens, and because direct proof is rare, courts let plaintiffs prove it indirectly by showing the defendant had access to the original and that the two songs are substantially similar in ways the law actually protects. Everything else in a music infringement case — expert musicologists, jury instructions, defenses, damages — flows from how a court works through those elements.
The Two Things a Plaintiff Must Prove
A copyright owner has to establish ownership of a valid copyright and show that the defendant copied protected elements of the work. Federal law requires the Copyright Office to have actually processed the registration (or refused it) before a lawsuit can be filed.1Office of the Law Revision Counsel. 17 USC 411 – Registration and Civil Infringement Actions A pending application is not enough. That procedural gate, confirmed by the Supreme Court in Fourth Estate Public Benefit Corp. v. Wall-Street.com, means a songwriter who hasn’t registered before discovering an infringement faces a wait before they can get into court at all.
Copying is proven two ways. Occasionally there is direct evidence. More often, the plaintiff shows the defendant had access to the original work and that the two works share substantial similarity. Access can come from wide commercial release of the earlier song, shared producers or collaborators, or evidence the defendant heard it. Strong access evidence used to lower the similarity bar in the Ninth Circuit under the “inverse ratio rule,” but the court scrapped that doctrine in its 2020 en banc Skidmore v. Led Zeppelin decision, calling it illogical.2Justia. Skidmore v Zeppelin, No. 16-56057 (9th Cir. 2020) Even where access is obvious, the plaintiff still has to prove meaningful musical overlap.
One structural point matters before the similarity analysis even starts: every recorded song carries two separate copyrights. The musical composition covers the melody, harmony, lyrics, and arrangement, and usually belongs to the songwriter or publisher. The sound recording covers the specific captured performance and usually belongs to the record label. These are independent works, and infringing one does not automatically infringe the other.3U.S. Copyright Office. Musical Works, Sound Recordings and Copyright Compositional similarity claims and sampling claims get analyzed differently because they target different rights.
The Substantial Similarity Test
Substantial similarity is where most music copyright cases are won or lost. Courts in the Ninth Circuit use a two-part framework that other circuits have largely adopted in some form, and both parts must be satisfied for infringement to be found.4Ninth Circuit District and Bankruptcy Courts. 17.19 Substantial Similarity – Extrinsic Test; Intrinsic Test
The Extrinsic Test
The extrinsic test is an objective comparison of specific expressive elements. This is where forensic musicology does the work. Expert witnesses break the songs down into their components and compare melodic contour, pitch sequence, rhythm, and harmonic progression. The critical task is separating protectable creative choices from unprotectable building blocks. A descending minor scale, a standard chord progression, or a familiar genre convention belongs to everyone. An unusual melodic phrase set against an unexpected rhythmic pattern may not.
The Intrinsic Test
The intrinsic test asks whether an ordinary listener would find the songs substantially similar in overall concept and feel. No expert testimony is permitted. This is the jury’s own ear. A song can clear the extrinsic test on paper and still fail the intrinsic test because the overall impression is different, and vice versa.
Protectable Expression vs. Musical Building Blocks
The line between what a songwriter can own and what belongs to every songwriter is the single most important issue in modern music copyright litigation. Three recent cases show how courts are drawing it.
In Williams v. Gaye, a jury found that Pharrell Williams and Robin Thicke’s “Blurred Lines” infringed Marvin Gaye’s 1977 “Got To Give It Up.” The Ninth Circuit affirmed, holding that the Gaye composition was entitled to broad copyright protection and that musical works are not confined to a narrow range of expression.5Justia. Williams v Gaye, No. 15-56880 (9th Cir. 2018) The final judgment was approximately $5 million plus 50% of future royalties. The decision alarmed songwriters and musicologists because the infringement finding appeared to rest on shared groove and stylistic feel rather than note-for-note copying.
Skidmore v. Led Zeppelin pulled hard in the opposite direction. The estate of Randy Wolfe claimed Led Zeppelin’s “Stairway to Heaven” copied a descending chromatic line from the Spirit instrumental “Taurus.” The Ninth Circuit, sitting en banc, affirmed the jury verdict for Led Zeppelin, holding that commonplace musical elements rooted in a genre’s tradition cannot receive exclusive rights, even when combined, and that a few shared notes are not enough.2Justia. Skidmore v Zeppelin, No. 16-56057 (9th Cir. 2020) The ruling expressly cabined the broader reading of Williams.
Gray v. Hudson confirmed the direction. A jury initially found that Katy Perry’s “Dark Horse” infringed the Christian rap track “Joyful Noise” and awarded $2.8 million. The Ninth Circuit reversed, finding that the shared repeating note pattern was essentially a two-note snippet of a descending minor scale with repeated notes, lacking the originality copyright protects.6Justia. Gray v Hudson, No. 20-55401 (9th Cir. 2022) Basic musical elements and predictable arrangements of them are free for everyone to use.
The practical takeaway for anyone trying to predict how a case will come out: the extrinsic analysis sweeps generic material off the table first. What’s left is what the jury compares. If the surviving material is thin, the claim rarely wins.
Sampling Is Decided Differently
The analysis above governs compositional similarity. Physical sampling of a sound recording follows a different rule in the Sixth Circuit. In Bridgeport Music v. Dimension Films, the court held that copying any portion of a copyrighted sound recording, no matter how small, constitutes infringement. The court’s instruction was blunt: “Get a license or do not sample.”7Justia. Bridgeport Music Inc v Dimension Films, 410 F.3d 792 (6th Cir. 2005) Not every circuit has adopted that zero-tolerance approach, and some still apply a de minimis threshold to sound recording samples, so the governing rule depends on where the case is filed. Whether a sample infringes the underlying composition is a separate question that still requires the full substantial similarity analysis.
Defenses That Can Defeat the Claim
Being sued does not mean losing. Three defenses regularly do real work in music cases.
Independent Creation
Copyright does not prohibit two people from independently writing similar music. A defendant who can show the song was created without hearing or being influenced by the plaintiff’s work has a complete defense. Early demos, timestamped session files, production logs, and evidence that the defendant had no realistic path to hearing the plaintiff’s work all support the defense. The challenge is building that record before the lawsuit arrives.
Fair Use
Fair use allows limited unauthorized use for purposes like commentary, criticism, education, or parody. Courts weigh four factors:8Office of the Law Revision Counsel. 17 USC 107 – Limitations on Exclusive Rights: Fair Use
- The purpose and character of the use, with commercial uses weighing against fair use and transformative uses (such as parody that comments on the original) weighing in favor.
- The nature of the copyrighted work, with creative works like songs receiving stronger protection than factual works.
- The amount used, where taking a small, non-essential portion favors fair use and copying the heart of a song does not.
- The effect on the market, which cuts sharply against fair use when the new work substitutes for the original.
Fair use is notoriously unpredictable in music disputes. The defendant carries the burden, and the defense works best for clear parody or criticism. It rarely succeeds when a defendant simply used a hook or melody in a competing commercial track.
De Minimis Use
The de minimis doctrine holds that trivial or unrecognizable uses do not infringe. For compositions, a borrowed fragment so short or altered that no reasonable listener would recognize it may fall below the legal threshold. For sound recordings, Bridgeport eliminates the defense in the Sixth Circuit when the defendant physically lifted audio.7Justia. Bridgeport Music Inc v Dimension Films, 410 F.3d 792 (6th Cir. 2005) Whether de minimis applies to a sample is one of the questions driven by which circuit hears the case.
Timing of the Claim
A copyright owner must file suit within three years after the claim accrues.9Office of the Law Revision Counsel. 17 USC 507 – Limitations on Actions Under a discovery rule theory, the clock starts when the owner discovers (or reasonably should have discovered) the infringement. In Warner Chappell Music v. Nealy (2024), the Supreme Court held that a copyright owner with a timely claim can recover damages for infringement that occurred long before the lawsuit was filed, with no separate backward-looking time limit on monetary recovery.10Supreme Court of the United States. Warner Chappell Music Inc v Nealy (2024) The Court did not definitively resolve whether the discovery rule applies to copyright cases, assuming it did for purposes of the holding.
What a Winning Plaintiff Recovers
The remedies available shape how aggressively each side litigates.
A plaintiff can elect actual damages plus the infringer’s profits attributable to the infringement, with no double-counting between the two categories. In music cases, this usually requires detailed accounting of streaming revenue, licensing fees, and tour income tied to the infringing track.
Alternatively, a plaintiff can elect statutory damages and avoid proving exact losses. The range runs from $750 to $30,000 per infringed work, and if the court finds the infringement was willful, the ceiling rises to $150,000 per work.11Office of the Law Revision Counsel. 17 USC 504 – Remedies for Infringement: Damages and Profits The willfulness finding depends on whether the defendant knew about the infringement or acted with reckless disregard, and it is often the difference between a painful verdict and a catastrophic one.
Courts also have discretion to award reasonable attorney’s fees to the prevailing party on either side.12Office of the Law Revision Counsel. 17 USC 505 – Remedies for Infringement: Costs and Attorneys Fees Injunctive relief is also available and can be severe: a permanent injunction effectively ends the commercial life of the infringing track by forcing platforms and retailers to pull it.13Office of the Law Revision Counsel. 17 USC 502 – Remedies for Infringement: Injunctions Between fee-shifting, enhanced statutory damages, and the possibility of pulling a song from the market entirely, the stakes are high enough that most of these disputes settle well before a jury ever hears them.