There's a lady who's sure, but the Ninth Circuit isn't when it comes to a copyright case involving Led Zeppelin's “Stairway to Heaven.”

The full court agreed Monday to review a three-judge panel decision that ordered a new trial for the estate of songwriter Randy Wolfe, which alleges that the first few measures of the '70s classic copies from a song called Taurus that Wolfe composed a few years earlier.

Led Zeppelin's Robert Plant and Jimmy Page and publisher Warner/Chappell Music Inc. had escaped liability at trial. They argued the Ninth Circuit's decision will make it too easy to copyright simple chromatic scales, arpeggios and short sequences of notes.

They're backed by an amicus curiae group of musicians and producers. “At the very minimum, these rulings are certain to cause substantial confusion among songwriters, who only have twelve notes with which to work in the first place,” Edwin McPherson of McPherson Rane wrote for the amici. “Songwriters need at least some certainty as to what basic elements of music are free for all to use.”

Francis Malofiy of Francis Alexander, who represents the trustee of Wolfe's estate, Michael Skidmore, asked for rehearing too. While Malofiy contends the decision was mostly correct, he argued it erred by holding that the sheet music deposited with the Copyright Office determines the scope of copyright for pre-1978 recordings. “In effect, most blues, jazz, folk and rock and roll music composed before 1978 is now no longer copyrighted due to the panel's ruling,” Malofiy argues.

Judge Richard Paez led the three-judge panel that originally ruled last September. He wrote that U.S. District Judge R. Gary Klausner should have instructed jurors that the selection and arrangement of unprotectable elements can be protected expression. A simple descending chromatic scale used in combination with other elements in an original manner could warrant copyright protection, Paez wrote.

And even though the deposit copy defines the scope of the copyright, Klausner should have let jurors hear a recording of Taurus so they could better evaluate Page's testimony about his access to the song, Paez wrote. (Led Zeppelin and Wolfe's band Spirit occasionally toured together, and Page acknowledged owning an album that contains the song.)

Plant, Page and Warner/Chappell argued that en banc review is necessary to decide “a foundational question in every copyright case”—whether substantial similarity between the works or virtual identity is necessary to prove infringement. “This court has consistently required virtual identity when the claimed similarity is the selection and arrangement of unprotected elements,” argued the band's lawyer, Peter Anderson of the Law Offices of Peter J. Anderson.

Anderson argued the Ninth Circuit has gotten away from that standard in the Led Zeppelin case and the recent battle over the “Blurred Lines” song between Pharrell Williams and the heirs of Marvin Gaye. Judge Jacqueline Nguyen, who dissented in Williams v. Gaye, “noted the error,” he wrote.