Led Zeppelin guitarist Jimmy Page demonstrated a deft touch at deflecting questions aimed at showing he might have lifted a passage for the introduction to the 1971 hit "Stairway to Heaven."

Testifying in his defense Thursday in a copyright infringement case, Page showed little interest in comparing his composition with the obscure earlier instrumental work in question, "Taurus," by the late Randy Wolfe, founder of the band Spirit.

Page was reluctant to compare the harmony, tempo or structure of the two songs, thwarting the lawyer representing Wolfe's estate in the lawsuit against Led Zeppelin, Page and singer Robert Plant, as well as several music companies.

"You want to step through it," attorney Francis Malofiy asked as he tried to get Page to discuss the "Taurus" sheet music, which is the work protected by copyright.

"Not necessarily," Page replied, sending a ripple of comic relief through the gallery during an otherwise dull day of testimony in the case.

Page, 72, had entered the courtroom carrying a guitar, but wrapped up testifying without playing a note. The closest he came was during a break when he briefly struck a jamming pose and played air guitar and laughed with Plant in the courtroom.

Jurors and a packed audience in Los Angeles federal court did get to hear the familiar opening chords of "Stairway," but they came not from Page, but from an expert who said he found it strikingly similar to "Taurus."

Kevin Hanson, a guitar instructor and former member of Huffamoose, played passages from both songs on acoustic guitar and says they are virtually identical. When listening to videos of the two played simultaneously, he said there was nothing discordant about them.

"To my ear, they sound like they are one piece of music," he said.

On cross-examination, however, Hanson, who doesn't have a college degree and is not a musicologist, said he can easily tell the songs apart.

Another plaintiff expert, Alexander Stewart, a music professor at the University of Vermont, said he found five categories in which both songs had significant similarities, including a descending chord progression, notes lasting the same duration and a series of arpeggios and similar pairs of notes.

Stewart said the descending chord progression and other elements have been found in songs dating to the 1600s. But he testified that of more than 65 songs the defense has said have a similar construction, including "My Funny Valentine," the Beatles' "Michelle," and "Chim Chim Cher-ee" from the movie "Mary Poppins," none contained all five elements shared by "Taurus" and "Stairway."

"Not one of them came close," Stewart said, though he acknowledged on cross-examination that the notes in both songs didn't all line up in the same places.

The plaintiffs are expected to wrap up their case Friday with estate trustee, Michael Skidmore, concluding testimony and a financial expert taking the stand.

Malofiy tried unsuccessfully to introduce evidence of a $60 million deal Led Zeppelin signed for the rights to its catalog, but the judge wouldn't allow it because it was from 2008 and extends beyond the statute of limitations.

Page, wearing a suit, tie and his white hair pulled back in a ponytail, was asked about several contracts. Peering through his reading spectacles, he was asked to read the title on the document.

"Confidential," he said as the courtroom erupted with laughter.

One of the biggest challenges for the plantiffs is showing that "Stairway" is substantially similar to the sheet music for "Taurus" because that's what's filed at the U.S. Copyright Office.

The recording of "Taurus," which contains a riff very similar to the opening of "Stairway" is significantly different from videos of experts playing the sheet music.

Because the recording is not protected by the copyright, jurors can't consider it and it can't be played in court.

Malofiy tried several times to get Page, who said he never heard "Taurus" until comparisons began popping up online a few years ago, to compare the two songs. Page's lawyer successfully objected and the question was never answered.

However, when Page was asked to compare "Stairway" to the "Taurus" sheet music, he said he preferred to hear it.

"I'm asking if I can hear what was played," he said, knowing he couldn't.

To demonstrate the shortcomings of sheet music, though, Malofiy showed Page the copyright version of "Stairway to Heaven."

Page, who said he composed the music and Plant wrote the lyrics, said he had not written the sheet music he was shown.

It begins with the opening lyrics, "There's a lady who's sure/All that glitters is gold," eliminating the famous instrumental introduction that lasts nearly a minute.

"It's not there," Page said.