The surviving members of Led Zeppelin defended themselves in court in 2016 against a claim that they had plagiarized part of their biggest hit, "Stairway To Heaven”. The prosecuting attorney, Francis Malofiy, claimed that the band had ripped off the obscure 1968 Spirit instrumental "Taurus”, and his flamboyant presentational style and frequent clashes with the judge was melodramatic enough to warrant a box of popcorn. Ultimately, Led Zeppelin won the trial, but before the jury delivered the verdict to Malofiy and Led Zeppelin lead counsel Peter Anderson, Robert Plant, Jimmy Page and John Paul Jones all testified in court.

According to a new report published by Billboard, that copyright fight is now heading to a federal appeals court. In a 90-page brief filed Wednesday, attorney Francis Malofiy argues that it is "quite clear" that Page relied on "Taurus" when creating the iconic intro to "Stairway" and that the jury only found the songs were not substantially similar because of evidentiary errors and erroneous instructions.

"The most important of these errors was that the trial court refused to let the jury hear the full and complete composition of 'Taurus' embodied in the sound recordings that Jimmy Page possessed, instead limiting the comparison to an outline of the 'Taurus' composition in the deposit copy lead sheet," writes Malofiy.

That appeal even cites the Zeppelin decision, arguing that the court was proper in instructing the jury to disregard musical building blocks that aren't protected by copyright.  

Malofiy doesn't see it that way. He says the court erred by not explaining to the jury that "combinations of otherwise unprotectable elements can themselves be afforded protection."

Go to this location for the complete report.

Page's testimony made for some of the trial's most riveting moments. The guitarist was asked to compare "Stairway To Heaven" with the Mary Poppins song "Chim Chim Cher-ee”. At another point when Malofiy asked how long a riff was played in concert, Page said, "I don't have a stopwatch." And when the attorney observed that Page "had a gift in his ability to play guitar," the musician deadpanned, "Well, yeah," to laughter in the courtroom. In more serious moments, the band members described how they wrote one of rock's most enduring songs. The whole thing came off like scenes in a movie.

Read Page's full testimony at RollingStone.com.