Singer-songwriter John Mayer and film director and producer Joseph McGinty Nichol (known as McG) have teamed up to buy and renovate a piece of Hollywood history: the legendary movie studio built by Charlie Chaplin. Tracy Smith talks with Mayer, McG, and Hollywood historian Marc Wanamaker about the Chaplin Studios, its history as a soundstage and recording studio, and why it was important to preserve the production facilities' legacy, as a campus for artistic collaborations.