LOS ANGELES -- The stage was a federal courtroom. The band was Led Zeppelin. And the song was one of rock's best-known anthems.
The men credited with writing "Stairway to Heaven" were aging rockers wearing gray suits and white dress shirts, their once-flowing curly locks now shorter and pulled neatly to the back of their heads.
Singer Robert Plant and guitarist Jimmy Page weren't performing Tuesday in Los Angeles federal court, just listening quietly, along with a judge and eight jurors who will decide whether the opening of the 1971 ballad was lifted from a little-known instrumental tune written a few years earlier.
A lawyer for the estate of the late Randy Wolfe, also known as Randy California, claimed in opening statements that the British rockers lifted the passage from the instrumental tune "Taurus," recorded by Wolfe's band Spirit, and infringed on the copyright.
"This was a song that Randy California had written for the love of his life, Robin. That was her sign, Taurus," said attorney Francis Malofiy. "Little did anyone know it would fall into the hands of Jimmy Page and become the intro to 'Stairway to Heaven.'"
An attorney for Page and Plant said the two did not steal the tune and hadn't heard "Taurus" until decades after it was recorded.
"Forty five years ago, Jimmy Page and Robert Plant wrote some of the best songs in rock 'n' roll history," said attorney Peter Anderson, who claimed Wolfe's estate doesn't even own the copyright to "Taurus." "'Stairway to Heaven' was written by Jimmy Page and Robert Plant, and them alone."
At question is whether the opening two minutes played on guitar is substantially similar to Wolfe's work - a lesser-known song from a band that had several albums on Billboard's Top 200 record chart in the 1960s and '70s.
U.S. District Judge R. Gary Klausner ruled in April that evidence presented in hearings made a credible case that Led Zeppelin may have heard "Taurus" performed before their song was created.
Both pieces are based on a descending chromatic chord sequence in A minor that was used in other well-known pieces, such as "My Funny Valentine," said Joe Bennett, a forensic musicologist at the Boston Conservatory at Berklee.
"It's a well-used musical device. We can say with certainty that that chord sequence is not original," he said. "It wasn't written originally in 1968" when "Taurus" was released.
The chord progression dates back as far as the 1600s and other similarities also exist, Anderson said.
"Do re mi appears in both songs," Anderson said.
As the opening minutes of "Stairway to Heaven" were played, Plant looked at the jury and Page nodded his head to the tune. Anderson then played a recording of a piano interpretation of "Taurus" that had only a vague similarity.
Malofiy showed videos of guitar interpretations of both songs, which sounded more alike. When played simultaneously, similarities and differences were audible and could be seen in the finger work.
Wolfe's song formed the basis for the riff that made the "Stairway to Heaven" instantly recognizable, Malofiy said
Led Zeppelin opened for Spirit in their debut U.S. show in December 1968 in Denver, Malofiy said.
He said Led Zeppelin began its career by covering songs and would later change them stylistically in an effort to make them their own.
"Sometimes they crossed that bar, sometimes they didn't," he said.
The band has settled several similar copyright disputes over songs such as "Whole Lotta Love" and "Dazed and Confused," but the judge has barred Malofiy from introducing evidence from those cases.
"Stairway to Heaven" has generated hundreds of millions of dollars over the years.
Wolfe drowned in 1997 saving his son in Hawaii. His estate's trustee, Michael Skidmore, was able to sue the band, Warner Music Group Corp., Atlantic Recording Corp. and others after a 2014 change in the law allowed lawsuits for continued copyright infringement, Malofiy said.
Page, Plant and bandmate John Paul Jones are all expected to testify at the trial, though Jones has been dismissed as a defendant in the case.