A US appeals court has ordered a new trial in a lawsuit accusing Led Zeppelin of copying an obscure 1960s instrumental for the intro to its classic 1971 rock anthem Stairway To Heaven.
A federal court jury in Los Angeles two years ago found Led Zeppelin did not copy the famous riff from the song Taurus by the band Spirit.
But the three-judge panel of the 9th US Circuit Court of Appeals ruled unanimously that the lower court judge provided erroneous jury instructions. It sent the case back to the court for another trial.
A trustee for the estate of late Spirit guitarist Randy Wolfe filed the lawsuit against Led Zeppelin in 2015.
Jurors returned their verdict for Led Zeppelin after a five-day trial at which band members Jimmy Page and Robert Plant gave evidence.
Page and Plant, who wrote the lyrics, said their creation was an original.
The trial took jurors and observers who managed to pack into the courtroom on a musical journey through the late 1960s and early 1970s, when Spirit, a California psychedelic group that blended jazz and rock was achieving stardom as the hard-rocking British band was being founded.
The jury found Stairway To Heaven and Taurus were not substantially similar, according the 9th Circuit ruling.
But 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, 9th Circuit Judge Richard Paez said.
Mr Klausner also wrongly told jurors that copyright does not protect chromatic scales, arpeggios or short sequences of three notes, the 9th Circuit panel found.
“This error was not harmless as it undercut evidence by Skidmore’s expert that Led Zeppelin copied a chromatic scale that had been used in an original manner,” Mr Paez said.