By Daniel Kreps Fresh off Weezer announcing their The Gathering tour, the band staged an acoustic rooftop concert in Venice Beach on Friday, the latest in a series of pop-ups to mark their upcoming trek and new single. Rivers Cuomo and company set up Let It Be-style atop the Hinano Cafe to deliver a five-song acoustic set that included Weezer classics like “Undone – The Sweater Song,” “Buddy Holly,” “Island in the Sun,” and “Say It Ain’t So,” as well as “Go Away” featuring guest Best Coast’s Bethany Cosentino. Weezer have scheduled a series of pop-ups and surprise events around the Los Angeles area in what they’re calling “Weezer: The Gathering – Initiation Week,” like a Weezer-themed trivia night at a local bar and pickleball tournament (featuring the band members) scheduled for March 30. Weezer’s The Gathering Tour kicks off September 8 in Sacramento and spans 32 shows, looping around the U.S. and Canada before concluding in Los Angeles on October 24.…