Write a warm, engaging news report that ties together three recent music stories: John Mayer’s tribute to Bob Weir at a San Francisco memorial, Sammy Hagar’s switch of keyboard players for his summer tour, and Led Zeppelin’s solo albums as discussed in a feature about the best and worst among Jones, Page, and Plant. Use the details provided to describe the moments, quotes, and context from each piece, linking them with a common thread about legacy, collaboration, and evolution in rock. Invite readers to explore the sources for more on each artist’s ongoing projects and reflections.