British rock band Led Zeppelin on Monday effectively won a long-running legal battle over claims it stole the opening guitar riff from its signature 1971 song “Stairway to Heaven.” The band, one of the best-selling rock acts of all time, was handed victory after the U.S. Supreme Court declined to take up the case, meaning that a March 2020 decision by a U.S. appeals court in Led Zeppelin’s favor will stand. Lead singer Robert Plant and guitarist Jimmy Page had been accused in the six-year-long case of lifting the riff — one of the best-known openings in rock music —...