Perhaps the thing I love most about intellectual property law is that it deals with the intellectual pursuits that make life worth living: music, art, literature, technology and science. No other area of law could combine what has been described as the “greatest rock song of all time” and the question of whether that song infringes the rights of the author of an earlier musical composition. That, however, is precisely the issue the U.S. Court of Appeals for the Ninth Circuit decided on March 9 in a case involving the Led Zeppelin rock masterpiece “Stairway to Heaven.”

In 2014, nearly 40 years after Led Zeppelin released “Stairway,” the estate of Randy Wolfe—a guitarist from the band Spirit who performed under the moniker “Randy California”—sued Led Zeppelin, its members Jimmy Page, Robert Plant and John Paul Jones, and various other music industry companies, claiming that the song had been copied from an instrumental song written in 1966 or 1967 called “Taurus.”