The Philadelphia-based “dj pressed” will spin tunes accompanied by clips from the long-running FX comedy at the Howard Theatre. The club is organizing a “Youth Day” introductory session in Marriottsville, Md., on Aug. 15, minus the pool and booze. The ensemble holds a three-day intensive each summer, open to anyone who plays the mandolin, mandola, mandocello, classical guitar or upright bass. It’s unclear how exactly this merry band of musicians will celebrate the Declaration of Independence, but the event culminates with a free community concert called, “America at 250: We the People, All of Us.” More to explore: Final weekend to see the critically hailed “American Aspirations” exhibit at the Smithsonian Institution Building.