When it comes to making art, what's the difference between inspiration and theft? That's the question at the heart of one of the biggest musical copyright trials in years that began this week.

Transcript

MELISSA BLOCK, HOST:

What's the difference between musical inspiration and intellectual theft? That's the question at the heart of a big copyright trial that began this week in a federal court in Manhattan.

(SOUNDBITE OF SONG, "LET'S GET IT ON")

MARVIN GAYE: (Singing) I've been really trying, baby.

BLOCK: "Let's Get It On" was performed by Marvin Gaye, but it was co-written by Ed Townsend. And Ed Townsend's heirs have accused another musician of writing a song that copies "Let's Get It On."

(SOUNDBITE OF SONG, "THINKING OUT LOUD")

ED SHEERAN: (Singing) And, baby, my heart could still fall as hard at 23.

BLOCK: That's "Thinking Out Loud" by the British musician Ed Sheeran. Adrian Ma and Wailin Wong from our daily economics show The Indicator From Planet Money explain why this case of Ed v. Ed should matter to music lovers everywhere.

ADRIAN MA, BYLINE: When she was just a kid, Jennifer Jenkins thought she might grow up to be a musician.

JENNIFER JENKINS: I had dreams of being a rock star. I played the piano, played the violin, played the flute, was not terribly good at any of them.

WAILIN WONG, BYLINE: Jennifer became a law professor, but she is still a music nerd. She specializes in music copyright law, and she still plays piano.

JENKINS: (Playing piano).

MA: And so Jennifer seemed like the perfect person to explain how music copyright infringement cases like the case of the two Eds get decided.

WONG: She says to understand this case, you have to go back to 1946, to a case called Arnstein v. Porter. Now, the porter was Cole Porter, famous composer of various show tunes and jazz standards like "Night And Day."

(SOUNDBITE OF SONG, "NIGHT AND DAY")

ELLA FITZGERALD: (Singing) I think of you...

WONG: Hey.

(SOUNDBITE OF SONG, "NIGHT AND DAY")

FITZGERALD: (Singing) ...Night and day.

MA: Oh, yeah, I love some Ella Fitzgerald. So Cole Porter - a household name. Ira Arnstein, on the other hand...

JENKINS: He was an unsuccessful songwriter, and he had what one commentator called persecution mania. He was just completely convinced that people were stealing his music, even though they probably weren't. And so if you look through the history of music copyright cases, you'll see all these cases called Arnstein versus this, Arnstein versus that.

WONG: Most of Arnstein's lawsuits got tossed out as baseless, but his lawsuit against Cole Porter would go down in legal history because in that case, the court came up with this two-part test for determining music copyright claims. The first question the jury would have to decide...

JENKINS: Are the similarities between these two songs - are they a complete coincidence? Or is there enough to justify an inference that copying occurred?

WONG: If a defendant never heard the plaintiff's song, then any similarity between the two is just a coincidence. And that's a defense in a copyright case.

MA: Though probably not in Ed Sheeran's case and not just because "Let's Get It On" is, like, a super-duper-famous song...

(SOUNDBITE OF ARCHIVED RECORDING)

SHEERAN: (Singing, inaudible).

MA: ...But also because during this concert several years ago, Ed Sheeran was in the middle of playing his song "Thinking Out Loud" and then briefly switched into...

(SOUNDBITE OF ARCHIVED RECORDING)

SHEERAN: (Singing) Let's get it on.

WONG: So he can't be like, Marvin Gaye - never heard of him.

MA: Right. He obviously maintains that there was no copying going on. But hypothetically, if a jury were to decide there was some copying happening, there is a second question they'd have to answer as part of the Arnstein test. And that is, did this copying somehow cross a line?

JENKINS: You know, was this inspiration or theft? Is it benign, OK appropriation, or is it unlawful appropriation?

MA: Right. Like, did one song copy really big chunks from another, or did it maybe just copy a little bit but that little bit was, like, the best, most original part of the song? So when you take all this together, that is the test that courts still use in music copyright cases today - part one, coincidence or copying; part two, inspiration or theft.

WONG: And if you're thinking out loud, this seems very subjective, Jennifer says you are exactly right.

JENKINS: The weird thing in music cases is there's often no authoritative text that tells us what we're even talking about, what the music even is. Typically, the judges or the jurors don't have musical backgrounds. And so who do they rely on to tell them what we're even talking about? That's the forensic musicologist.

MA: The forensic musicologist. Aside from the musicians in the cases, forensic musicologists are low-key the stars of any music copyright trial. And their title might conjure images of, like, a "CSI" detective dusting for fingerprints and collecting DNA. And it turns out it's kind of like that.

WONG: These forensic musicologists are experts in music theory who can break down and analyze every little piece of a song. In the case of the two Eds, both sides have their own forensic musicologists.

MA: It's probably important to mention here that forensic musicology is not a precise science. And for that reason, Jennifer says the arguments that get made in these cases can get a little fudgy. Like, for example, with "Let's Get It On" and "Thinking Out Loud," they may have different melodies and lyrics and instrumentation, but the plaintiff nevertheless argues that these songs share a key similarity.

JENKINS: So in the background of "Let's Get It On" is this chord progression. (Playing piano).

(SOUNDBITE OF SONG, "LET'S GET IT ON")

GAYE: (Singing) I've been really trying, baby.

JENKINS: OK. Here's what's going on in Ed Sheeran. (Playing piano).

(SOUNDBITE OF SONG, "THINKING OUT LOUD")

SHEERAN: (Singing) Baby, my heart could still fall as hard at 23.

JENKINS: That's what this case is about.

MA: That's - wait.

JENKINS: I'm serious.

MA: So I just - I almost...

JENKINS: Totally serious.

MA: I went - that happened so fast, I almost missed it. So that's - the main argument in this case is that.

JENKINS: Yep.

MA: And here's the thing. Chord progressions, a lilting rhythm - these are just basic musical building blocks. I mean, there are only 12 notes in the Western musical scale, you know, only so many of those combinations of them that people actually want to hear.

WONG: And yet that hasn't stopped plaintiffs in recent years from claiming ownership seemingly over basic musical bits. Like, a few years ago, you may have heard of the case involving a song called "Blurred Lines."

(SOUNDBITE OF SONG, "BLURRED LINES")

PHARRELL: Everybody get up.

WONG: Robin Thicke and Pharrell Williams were accused of copying another Marvin Gaye song, "Got To Give It Up."

(SOUNDBITE OF SONG, "GOT TO GIVE IT UP")

GAYE: (Singing) I used to go out to parties.

MA: In that case, the plaintiff argued that, look; both songs have this, like, funky bassline and this cowbell part, and those are all evidence of copying. And the jury agreed, which promptly freaked out the music industry and had songwriters and record companies looking over their shoulder for the next few years. Some even took out insurance policies and hired forensic musicologists to pre-vet their songs.

WONG: So what does this all mean for the case of the two Eds?

JENKINS: I'm not, like, weeping tears for Ed Sheeran either way. That's not what this is about, right? This is about all musicians. This is about the musical commons. And this is about whether anyone, including the next Ed Townsend and the next Marvin Gaye, can use these basic building blocks when writing their own songs. If they can't, then the songwriter's toolkit has been severely diminished, and that's bad for music.

MA: Regardless of her views on the case, Jennifer says she really has no idea who will win. She says juries can be unpredictable, and this area of law is kind of blurred. Adrian Ma.

WONG: Wailin Wong, NPR News. Transcript provided by NPR, Copyright NPR.

Tags: Ed Sheeran