The Song Does Not Stay the Same.

Led Zeppelin won the plagiarism lawsuit over "Stairway to Heaven," perhaps their most famous song. A jury at the U.S. District Court in Los Angeles ruled that the heirs of Randy California were unable to prove plagiarism of the song "Taurus," composed in 1968 by Spirit.
The lawsuit began in 2014, and according to the plaintiffs, Led Zeppelin were aware of the song "Taurus," which they subsequently copied and released on their famous album IV. The song "Taurus," however, had previously appeared on Spirit’s self-titled debut album from 1968.
The federal court jury, while confirming that Jimmy Page and Robert Plant were aware of the riff from the song "Taurus" as early as 1967, agreed that there was no total or partial plagiarism on the part of the British rock band.