Led Zeppelin founders Robert Plant and Jimmy Page are facing plagiarism charges of their iconic 1971 anthem 'Stairway To Heaven'.

During the first day of the trial, attorney Larry Iser referenced the Beatles' 'While My Guitar Gently Weeps' in his opening statement. Iser, who has represented the Beatles and Michael Jackson, said that the opening guitar riff and descending bass line are a universal musical transition that had been used on 'While My Guitar Gently Weeps' and on Zeppelin's 'Babe I'm Gonna Leave You'.

Neither Plant, nor Page spoke during today's appearance in court.

The original complaint was brought by the band Spirit's trustee Michael Skidmore. Skidmore's claim was Spirit's guitarist Randy Wolfe should be given writing credit on the classic Zeppelin song.

The judge remarked that, "While it is true that a descending chromatic four-chord progression is a common convention that abounds in the music industry, the similarities here transcend this core structure," the judge remarked. "What remains is a subjective assessment of the 'concept and feel' of two works ... a task no more suitable for a judge than for a jury."