Every once in awhile, a concert winds up being more notable as an event than as a pure live-music experience. Case in point: J. Cole's secret concert at House of Blues. The North Carolina rapper announced the latest round of his ongoing Dollar and a Dream tour would kick off in Dallas at a location to be disclosed the day of the show. Sure enough, on Sunday, June 21, about 4,000 people converged on downtown in hopes of getting in. Police showed up, unaware of what was happening, and social media was flooded with photos and videos. How's that for inspired promotion?