Mr. Wolfe never pursued a lawsuit during his lifetime. But Mr. Skidmore, a customs consultant and former music journalist who has controlled Mr. Wolfe’s trust since 2009, filed the case in 2014, shortly after a Supreme Court ruling that said that copyright infringement cases could proceed even after long delays.

Mr. Page and Mr. Plant deny ever having heard “Taurus” before the case came to light and say that “Stairway to Heaven” was written independently. Yet over the years, the band has settled numerous challenges of plagiarism by adding other songwriters’ credits to its albums. In 2012, for example, the band settled a suit by Jake Holmes over “Dazed and Confused,” and subsequent releases of the song on Led Zeppelin’s albums list it as being written by Mr. Page and “inspired by Jake Holmes.”

Whatever happens with the Led Zeppelin trial, the industry is still trying to understand the effects of the “Blurred Lines” case, which is under appeal.

Matt Pincus, the chief executive of Songs Music Publishing, an independent publisher that works with current pop and hip-hop acts like the Weeknd and Desiigner, said his company was seeing far more claims of infringement now — most made privately, outside of court — than ever before. But the reasons were not clear, he said.

“It could be opportunism, because lawyers are smelling blood,” Mr. Pincus said. “But it could also be because we have moved to a real collaboration economy now, where pop records have multiple collaborators in a way that they didn’t five or six years ago.” Those collaborators may dispute credits or royalties after the fact.

Richard S. Busch, the lawyer who represented the Gaye family in the “Blurred Lines” case, said that each copyright case succeeded or failed on its own merits, and he disputed the idea that his case has had any negative impact on the music industry.

“The fact that maybe some people are being caught now that wouldn’t be, or are being pursued now that wouldn’t be, is not a bad thing,” Mr. Busch said. “But the idea that ‘Blurred Lines’ has opened up the floodgates is absurd, and I would suspect that those who are claiming this may have an agenda to take that position.”