LOS ANGELES (AFP) - Led Zeppelin's Jimmy Page and Robert Plant will appear in court Tuesday to defend “Stairway to Heaven,” one of the most recognizable songs in rock history, from accusations of plagiarism.

Spirit, a psychedelic band from Los Angeles that enjoyed a niche following but never the superstardom of Zeppelin, claim the iconic melancholic guitar that opens the song was lifted from its instrumental track “Taurus.”

Spirit’s guitarist Randy Wolfe -- who went by the nickname Randy California -- never took legal action and died in 1997, but a lawsuit was filed by his trustee Michael Skidmore.

“Well, if you listen to the two songs, you can make your own judgment. It's an exact ... I’d say it was a rip-off,” California said in a magazine interview just before his death, quoted in the lawsuit.

“And the guys made millions of bucks on it and never said ‘Thank you,’ never said, ‘Can we pay you some money for it?’ It's kind of a sore point with me.”

After two years of legal proceedings, a judge stopped short of agreeing that the song was copied, but said there was enough of a case for a jury trial in Los Angeles.

Spirit’s representative “failed to proffer evidence of striking similarity, but he has successfully created a triable issue of fact as to access and substantial similarity,” U.S. District Court Judge Gary Klausner said in a ruling in May.

The judge said the two sides had “vehemently contested” the question of whether Led Zeppelin had access to 1967's “Taurus” before recording “Stairway to Heaven” in London in December 1970 and January 1971.

Led Zeppelin was the opening act for Spirit when the hard British rockers -- Plant, Page, John Paul Jones and the since deceased John Bonham -- made their U.S. debut on Dec. 26, 1968 in Denver.

But surviving members of Led Zeppelin submitted testimony to the court that they never had substantive interaction with Spirit or listened to the band’s music.

‘Rock’s greatest song’

Once thought unlikely to appear, guitarist Page and singer Plant have already sat for filmed depositions and are expected to attend the opening of the trial in Los Angeles on Tuesday.

Opening statements are expected to be heard after the jury is sworn in.

Led Zeppelin argued that the opening of “Stairway to Heaven” -- a descending sequence mostly in A-minor -- had been used in music for centuries and that the lawsuit ignored the rest of the song, which builds over eight minutes.

The judge disagreed, writing that the two songs had additional similarities, including the bass line.

Skidmore has not specified the total in damages he is seeking but various stories in the music press have posited a possible settlement at anywhere between a symbolic $1 plus a writing credit to as much as $40 million.

The lawsuit, originally filed in Pennsylvania, says Led Zeppelin have “a deep-rooted history of lifting composition from blues artists and other songwriters who they have repeatedly failed to credit.”

It lists disputes over 16 other Led Zeppelin songs, many of which were settled by giving the complainant a songwriting credit and royalties, including classics “Whole Lotta Love” and “Babe I’m Gonna Leave You.”

“Randy California deserves writing credit for ‘Stairway to Heaven’ and to take his place as an author of rock’s greatest song,” the lawsuit asserts.

The case comes amid a rise in such copyright hearings, with the family of Marvin Gaye last year controversially winning more than $7 million from a jury over the song “Blurred Lines” by Robin Thicke and Pharrell Williams.

The judge rejected Led Zeppelin’s argument that it was too late to file a lawsuit, pointing out that the band released a remastered version of “Stairway to Heaven” in 2014.

But he said Skidmore would be entitled only to half of any amount in damages as California had signed a contract giving 50 percent of royalties to his music publisher.