A new trial will be held in a lawsuit that accuses Led Zeppelin of copying a 1960s instrumental in its 1971 classic Stairway To Heaven.
An earlier trial saw a federal court jury in Los Angeles find in favour of Led Zeppelin, but the US appeals court has since ruled that the judge in the original trial had given misleading instructions to jurors.
The instructions were regarding copyright law, which was a vital part of the suit.
The lawsuit was brought in 2015 by Michael Skidmore, a trustee for the late Randy Wolfe, who was guitarist of rock band Spirit and composed an instrumental called Taurus in 1967.
Mr Skidmore says the two bands toured together in 1968 and 1969 and this may have been when Led Zeppelin guitarist Jimmy Page was inspired to write Stairway To Heaven.
According to Mr Skidmore’s lawsuit, Wolfe had complained about the similarity between the two songs not long before he drowned in 1997 while attempting to rescue his son.
Plant and Page, however, say that Wolfe was a songwriter for hire and, therefore, had no claim to copyright.
They also say that the chord progressions in Stairway To Heaven were too well-known for such protection.
The judge in the first trial, R Gary Klausner, was found to have failed to tell 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.