Michael Putland/Getty ImagesThe copyright-infringement lawsuit involving Led Zeppelin‘s “Stairway to Heaven” is moving forward, and is set to go to trial starting May 10. Bloomberg reports that U.S. district court judge R. Gary Klausner decided Friday that a jury must decide whether the British rock legends copied the intro to the California group Spirit‘s 1968 instrumental “Taurus” in writing their famous tune.

In connection to his ruling, the judge said that although there wasn’t a “striking similarity” between the two songs, enough evidence existed for a jury to be asked to determine whether the tunes bore a “substantial similarity.”

Led Zeppelin guitarist Jimmy Page and singer Robert Plant, who co-wrote “Stairway to Heaven,” are expected to give testimony during the trial. According to Bloomberg, the rockers’ attorneys requested that the judge exclude evidence that “adverse effects of drinking or drug use in the 1960s or later” may have played a role in Page and Plant’s allegedly poor memory regarding whether they were familiar with the song they’re accused of plagiarizing.

The lawsuit was filed in 2014 by representatives of the estate of the late Spirit guitarist Randy California, who wrote “Taurus.” California, who was born Randy Wolfe, reportedly had claimed for years that the opening of 1971’s “Stairway to Heaven” was copied from “Taurus,” which appeared on his band’s 1968 debut album. Led Zeppelin did play on the same bill as Spirit in 1968 and ’69.

In addition, Michael Skidmore, trustee of Randy’s estate, claims that Page asked California to teach him the chords to “Taurus” sometime during 1969.

While the statute of limitations has run out on the Led Zeppelin members being liable for back royalties, if they lose the trial they could be required to pay royalties earned by “Stairway to Heaven” moving forward from when the lawsuit was filed.

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