Led Zeppelin signature song Stairway to Heaven is in the spotlight over allegations its opening chords were stolen from another work by the band Spirit. (Reuters)

For music geeks, what has unfolded in a Los Angeles courthouse over the past week has been like some epic Rock and Roll Hall of Fame induction ceremony — except with everyone wearing suits, and way too many lawyers in the room.

First, it was legendary axeman Jimmy Page at the mic. Then his longtime Led Zeppelin bassist and keyboardist John Paul Jones. And on Tuesday, it was their charismatic frontman Robert Plant — whose soaring screech and bare-chested swagger set a standard for 1970s rockers — who took the witness stand to insist that the band did not steal the opening chords of their defining song, “Stairway to Heaven,” from less-famous musicians.

[UPDATE, 6/23: Jury reaches verdict — Led Zeppelin did not plagiarize ‘Stairway to Heaven’]

Plant testified that he had no recollection of the 1968 instrumental tune “Taurus,” by the psychedelic rock band Spirit, and that it did not inspire Led Zeppelin’s 1971 hit. “I didn’t remember it then, and I don’t remember it now,” he declared, according to Rolling Stone.

And as for claims that he attended a Spirit concert where he might have heard it — well, Plant noted that he was in a bad car accident only hours later — “part of the windshield buried in the top of my head, which was interesting,” he noted dryly, according to the Independent — and had no memory of the prior evening.

“I don’t have a recollection of mostly anybody I’ve hung out with,” he added, which, according to the Hollywood Reporter, prompted raucous laughter in the gallery.

A courtroom sketch of Robert Plant, left, and Jimmy Page at the trial. (Mona Edwards/Reuters)

Over the past several days, some entertainingly quirky testimony — that has included spontaneous air drum performances, a slew of wry Britishisms and some vivid descriptions of Plant’s mop of wild curls — has distracted somewhat from the seriousness of the copyright infringement claim that the estate of the late songwriter Randy Wolfe, a.k.a. Spirit founder “Randy California,” has leveled against Led Zeppelin.

[Of course, Jimmy Page testified like a rock star in the ‘Stairway to Heaven’ trial]

The two bands toured together in the late 1960s, according to court records. The Zeppelin rockers have maintained that they don’t recall watching Spirit perform or socializing with members of the band. But others — including Spirit bassist Mark Andes and Michael Ware, a fan who testified on behalf of the plaintiff — offered conflicting recollections. Ware testified last week that he saw Plant at a Spirit show at the Mother’s Club in Birmingham, England, the Wrap reported. (And how could Ware be sure the man he saw was Plant, in the midst of a jam-packed venue more than 40 years ago? Because he spotted Plant’s “distinctive long, corkscrew blond hair,” of course.)

But even if Plant had heard Spirit perform “Taurus” live, he maintained he couldn’t have transcribed the notes for his guitarist and songwriting partner Page. When defense attorney Peter Anderson asked Plant if he could read or write music, he laughed, according to the Hollywood Reporter. “I haven’t learned that yet,” he said.

Plant then recounted the creation story of “Stairway to Heaven,” replete with all the evocative nostalgia and mysticism that diehard Zep fans might hope for.

[A shattering revelation about “Stairway to Heaven"]

Plant echoed Page’s testimony, according to reports, noting that the song was actually born when Page first played the opening notes while the men sat by a fire at Headley Grange — a rural recording and rehearsal retreat in England that was frequented by other popular bands at the time, including Fleetwood Mac and Genesis. (This tiny detail about geography galvanized rock nerds around the world, since legend has long held that the song was written at the Plant family vacation home, a Welsh cabin called Bron-Yr-Aur, which later lent its name to a pair of other Led Zeppelin songs and became a pilgrimage site for serious Zepheads.)

Plant said he had already been forming the lines that would become the song’s opening lyrics — a couplet that channeled “the natural, old, almost unspoken” culture of the Welsh landscape, according to the Los Angeles Times. Plant’s lines were paired with Page’s riff, and the song, an eight-minute anthem rich with Celtic iconography, began to take shape.

“I was trying to bring in the beauty and remoteness of pastoral Britain,” Plant said, according to the Independent. “It developed into something I could not imagine.”

Prompted by Anderson, Plant then softly half-spoke, half-sang the lyrics from the stand, according to reports:

There’s a lady who knows all that glitters is gold,

and she’s buying a stairway to heaven.

When she gets there she knows if the stores are all closed,

with a word she can get what she came for.

News reports did not indicate if jurors got goosebumps, but it definitely sounded like a moment.

The trial continued Tuesday despite a request by Led Zeppelin attorneys, who argued that the proceedings should be halted because the plaintiff’s attorney, Francis Malofiy, had failed to show evidence to support the copyright infringement claim.

The complaint was filed by Michael Skidmore, a trustee for the estate of Wolfe, who drowned in the Pacific Ocean in 1997 after saving his young son from a rip tide. He had long claimed that the resemblance between “Taurus” and “Stairway to Heaven” was more than just a coincidence.

“People always ask me why ‘Stairway to Heaven’ sounds exactly like ‘Taurus,’ which was released two years earlier,” Wolfe wrote in the liner notes for the 1996 reissue of Spirit. He noted that Spirit’s oeuvre was not unfamiliar to his more famous colleagues. “I know Led Zeppelin also played ‘Fresh Garbage’ in their live set. They opened for us on their first American tour.”

Wolfe took a more accusatory tone in an interview later that year with Listener Magazine: “I’d say it was a rip off,” he said of the chord progression in question, according to 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.”

The high-profile dispute has lured star-struck gawkers to the courthouse and captivated rock fans, musicians and music writers alike; if Led Zeppelin is found to have committed copyright infringement, the verdict would carry significant repercussions for songwriters.

[It’s okay if you hate Robin Thicke. But the ‘Blurred Lines’ verdict is bad for pop music.]

The band has settled similar copyright infringement claims over other songs, including “Whole Lotta Love,” “Dazed and Confused” and “Babe I’m Gonna Leave You.”

Tim Gardner, an accountant who assists Led Zeppelin with its record-keeping, testified that “Stairway to Heaven” has not been as lucrative in recent years as the plaintiff’s attorney claimed — Gardner said Page had made about $615,000 and Plant had earned $532,000 since mid-2011, the time frame subject to potential financial award if the band is found guilty of copyright infringement, according to reports from the courtroom.

Skidmore and Andes say they want justice for Wolfe, claiming he was never given his due for contributing to Led Zeppelin’s hit song.

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

The eight-member jury began its deliberations Wednesday, according to reporters in the courtroom.