This past June, members of Led Zeppelin found themselves having to defend the origins of one of their most successful tracks -- "Stairway to Heaven." A jury ultimately ruled that Led Zeppelin's Jimmy Page did not lift the track from Spirit's song "Taurus," but the case is not quite over yet as the copyright fight is now heading to federal appeals court.

According to The Hollywood Reporter, in a 90-page brief filed this past Wednesday (March 15), attorney Francis Malofiy argued that it was "quite clear" that Jimmy Page relied on "Taurus" when creating the intro to "Stairway to Heaven" and that the jury arrived at their conclusion because there were evidentiary errors and erroneous instructions given during the proceedings.

"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. In the mid-'70s, the federal government began recognizing the copyright protection of the songs themselves instead of just relying on the sheet music.

Malofiy adds that the court erred by not explaining to the jury that "combinations of otherwise unprotectable elements can themselves be afforded protection." He also states that the district court didn't give the jury enough instruction on the inverse ratio rule, which provides that the higher the degree of access to a work that is proven the lower the bar for proving substantial similarity. Writes Malofiy, "Access and substantial similarity are inextricably linked, yet the jury was asked to render a verdict without a key instruction that describes this relationship."

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