The big musical happening this weekend, at least for enthusiasts of a certain bent, is the return of the garage-rocking Blackout fest assembled by the vinyl junkies at HoZac Records, which kicks off with an art-and-music show Thursday night at Bottom Lounge before beginning in earnest at the Empty Bottle the following night. The festival offers a couple dozen punky, psychy, scummy rock acts over the weekend, including headliners Davila 666, Redd Kross, and Roky Erickson. But if hanging out with guys and girls wearing jean jackets and pumping a lot of booze into their systems doesn’t appeal, this week’s Soundboard offers plenty of alternatives.