The lawsuit was originally filed in 2015 by Michael Skidmore, who is a trustee for the estate of Spirit guitarist Randy Wolfe who is deceased. The trial in 2016 was carefully watched by the music industry, and both Plant and Page denied stealing the riff. Page said he wrote the music and Plant the lyrics.
But now this retrial could see it getting a little trickier for Led Zeppelin. According to the Guardian:
The jury found Stairway to Heaven and Taurus were not substantially similar, according to the ninth circuit ruling. But it also said the US district judge R Gary Klausner failed to advise jurors that while individual elements of a song such as its notes or scale may not qualify for copyright protection, a combination of those elements may if it is sufficiently original, the ninth circuit judge Richard Paez said.
Klausner also wrongly told jurors that copyright did not protect chromatic scales, arpeggios or short sequences of three notes, the ninth circuit panel found.
“This error was not harmless as it undercut testimony by Skidmore’s expert that Led Zeppelin copied a chromatic scale that had been used in an original manner,” Paez said.