The reason is that the reversal gave one panel of the Ninth Circuit an opportunity to try to fix the Ninth Circuit's unhelpful legal framework for determining copyright infringement. But that isn't why the panel reversed. What merited reversal was the lack of another jury instruction about a basic and uncontroversial principle of copyright law that the parties agreed should have been there in some form. In short, the case is being reversed — and the Ninth Circuit is getting a chance to fix its own weird copyright law — because of what appears to have been a brain fart. Jury Instructions: An Introduction We all gasped when we heard about the reversal. Jury verdicts are hardly ever reversed. One of the few ways a jury verdict can be thrown out is if the jury was badly instructed in the law. Juries, naturally, don't bring any knowledge about the law with them when they serve. That's not their job, really. Their job is to weigh evidence, make credibility determinations, and so forth. But at some point, they need to be told what the law is, so they can take all that evidence they weighed and apply it to the law and render a verdict. How this is accomplished might surprise you. There are several ways for jury instructions to be prepared and delivered to a jury, but the main way is this. First, the parties' attorneys confer about what jury instructions they can agree on and jointly submit those instructions to the court. In this, they are aided by pattern jury instructions prepared at the circuit court's direction. But pattern jury instructions don't cover every aspect of every area of the law. You'd need ever-updating volumes to do that. Also, the pattern jury instructions aren't unassailable: a party might disagree with one and explain how it should be and why. For all other jury instructions, the parties submit their own versions of instructions they think address all of the legal issues being raised at trial, together with a short explanation of the legal authorities for their versions. The judge decides which version to use, or the judge might even craft his or her own version based on their own research. Are the instructions then typed up, collated and distributed to the jurors in a neat binder? Just because your work is made up of lots of unprotectable elements, that doesn't mean your work as a whole can't be protected by copyright. If you put those unprotectable elements together in an original way, then the way you put those elements together is protectable, though not the individual elements themselves. After all, you can theoretically dissect any creative work down into non-protectable elements: individual notes, individual words and phrases, individual brushstrokes, etc. It's what you do with those non-protectable elements that counts. Well, at least, not necessarily. When the plaintiffs finally got around to suing, Led Zeppelin argued among other things that any similarities between the songs were only for non-protectable elements, like the use of the chromatic scale. Both parties recognized the need for an instruction on this issue. They disagreed on what it should say. They submitted competing instructions for the judge to consider. Then came the jury charge, at the very end of the case, just before the jury began deliberations. The judge began to read the instructions. Now, normally, a party would have an opportunity to object on the record to an instruction. This is a prerequisite to complaining about it on appeal. But the judge here didn't want to hear any objections. He reasoned that, if the parties disagreed about an instruction in their submissions, it was reasonable to assume that they would object to an instruction that didn't match what they'd submitted. The parties waited for the instruction about what to do with works made up of unprotectable elements. This was good for Led Zeppelin, though not ideal. On the other hand, it was foreseeable at the time that the missing jury instruction could imperil a jury verdict in Led Zeppelin's favor assuming they could focus on it with 500 other things going on at that moment. On appeal, the strongest argument — that trial court was correct not to give the instruction — wasn't really available to Led Zeppelin because even it had suggested an instruction. Led Zeppelin tried anyway. Instead, it had to argue that the missing instruction made no difference to the jury's deliberations. That's where another major goof with the jury instructions came in. Copyright's Broad Scope Nearly all copyright cases will need an instruction about originality. Originality, however, is pretty easy to achieve. All that's really required is that the work be expressive i. It also excludes material the author copied from other works including those in the public domain , but only if the author actually copied them. Originality doesn't mean novelty, just that it's the author's independent expression. Pattern jury instructions aren't law and aren't always appropriate in every instance, but departure from them demands explanation. The court took the model instruction and added the stuff in bold and took out the stuff that's been struck through: An original work may include or incorporate elements taken from works owned by others, with the owner's permission. However, any elements from prior works or the public domain are not considered original parts and not protected by copyright. You might detect a pattern here as it were. The instruction about how to treat works consisting of non-protectable elements was left out. Now the instruction about originality includes a new sentence that emphasizes how non-protectable elements aren't protectable, without telling the jury that those non-protectable elements can be selected and arranged in a protectable way. But surely one of copyright law's hearts is that creativity can and often does build on the work of others. This idea is echoed in fair use. And it is echoed in the non-controversial idea that not every element of a work must be protectable for the work to be entitled to copyright protection. These two errors in the jury instructions aren't just about technicalities of a highly technical law. Goodness knows there's a lot of those in copyright law. No, they go to one of the basic tenets of copyright law: what it means to create. My charitable interpretation of all this is that the court had a major brain fart that Led Zeppelin's lawyers didn't see coming or didn't fully understand how perilous the consequences would be. The other interpretation is that this was a legal strategy that worked too well and backfired badly. I strongly suspect that a correctly instructed jury would have come to the same verdict, but the scale of this mistake is such that we can't safely assume that. I also strongly suspect Led Zeppelin will prevail on remand—after incurring more expense, lost time and anxiety. From 2012 to 2014, he was an adjunct professor at Vanderbilt University Law School, where he was teaching Copyright Law. He blogs at and tweets at.