Led Zeppelin guitarist Jimmy Page and singer Robert Plant are in a federal courtroom in Los Angeles on Tuesday for trial in a copyright lawsuit over their song "Stairway to Heaven."

First, the court will pick a jury to decide whether the members of Led Zeppelin ripped off the song's famous riff.

Page and Plant are named as defendants in the lawsuit brought by the trustee of late guitarist Randy Wolfe from the band Spirit. Attorneys for the trustee say 1971's "Stairway to Heaven" copies music from the Spirit song "Taurus," which Wolfe wrote in either 1966 or 1967.

Led Zeppelin and Spirit performed at some concerts and festivals around the same time, but not on the same stage.

A judge has ruled that evidence made a circumstantial case that Led Zeppelin may have heard "Taurus" before writing their song.