We’ve all heard of, and most likely snickered at, flash mobs. Now meet the newest incarnation: flash concerts. In a series that’s brought The Roots to NYC, Jermaine Dupri to Atlanta, Fat Joe to Philadelphia, Staind to Boston, Collective Soul to Dallas, The Wallflowers to Los Angeles, Louis XIV to San Francisco, and Frankie J to Miami, Los Lonely Boys will be playing tonight at RFK Stadium. The shows are all announced at the last…