TUESDAY: >> The Sea and Cake’s Sam Prekop does solo post-rock at the Black Cat. $12. Local singer Brandon Butler (formerly of Canyon) opens. WEDNESDAY: >> Get a huge dose of hipsterness when The Killers (at right) play Merriweather Post Pavilion. Bands-of-the-moment Keane, Louis XIV, Regina Spektor, and Maximo Park all open. Lawn tickets at $25 are still available at Ticketmaster. >> If you don’t feel like making the trek out to Merriweather, you can…