By Phoenix Tso

LOS ANGELES (Reuters) - Led Zeppelin singer Robert Plant and guitarist Jimmy Page have made $58.5 million over the years from "Stairway to Heaven," an expert testified in Los Angeles on Friday in a trial over alleged copyright infringement by the band's signature song.

British rock band Led Zeppelin is accused of stealing the opening riff to its 1971 classic from the 1967 instrumental "Taurus" by the American band Spirit. The lawsuit was brought by Michael Skidmore, a trustee for Randy Wolfe, the late guitarist of Spirit and composer of "Taurus."

In federal court in Los Angeles on Friday, Skidmore's attorneys called Michael Einhorn, an expert on music royalties, to testify about damages related to the case.

Einhorn said Plant and Page have made $58.5 million in total as composers of "Stairway to Heaven."

The lawsuit seeks a writing credit for Wolfe on the song and damages in an amount to be proven at trial.

The trial has been closely watched this week as Page, 72, and Plant, 67, attended court, both wearing suits with their long silver hair tied into ponytails.

Page took the witness stand on Wednesday and Thursday and was questioned on whether there were any similarities between "Stairway to Heaven" and "Taurus."

The British musician said he did not recall hearing "Taurus" until recently, after he had been made aware of comparisons being made between the two songs.

He also testified that the descending chromatic structure of the guitar riff at the center of the lawsuit is heard in numerous other songs, including "Chim Chim Cher-ee" from the 1964 Disney film "Mary Poppins."

Led Zeppelin's attorneys on Friday brought in music expert Lawrence Ferrara, who testified that the only similarity between "Taurus" and "Stairway to Heaven" was a "descending chromatic minor line progression."

Ferrara said that musical element was used 300 years ago, as well as in many pop songs since then.

Earlier in the trial, Skidmore's lawyers simultaneously showed the jury two video clips of expert Kevin Hanson playing the openings of both songs. Hanson said the two clips "play together as one piece of music. It is not discordant."

(Wrting by Piya Sinha-Roy; Editing by Frank McGurty and Leslie Adler)