Atlanta artists tread lightly in yesterday's Summer Jam main stage lineup. Waka Flocka performed in daylight, thrillingly rapping and talking about why rapping is unimportant at the same time. Later, Young Jeezy filled time created by Nicki Minaj's cancelled appearance with an extended set, that dug deep into his back catalog ("Soul Survivor," performed without Akon) and featured a guest verse by T.I., another still-burning Southern star. 2 Chainz towered above his collaborators during sprinkled guest verses. He performed his current single "Riot," but wasn't given a proper place in the lineup. In spite of this—no contest—Atlanta dominated Summer Jam's mood-propelling, between-set DJ performances. Cash Out's "Cashin Out" was the first track played on the stadium's loudspeakers (by my tally, it was played about 10 more times before the night's end), and there were no less than three Future singles given repeat spins (four if you count "Racks," which he wrote). But Future wasn't invited to perform, and won't perform tonight at Irving Plaza in New York either. His Pluto tour, an ambitious large-venue outing with Pusha T, has been unceremoniously (and devastatingly) cancelled. He has yet to publicly comment, but between some smaller shows, Future will spend the newly-acquired free time working on a new mixtape, Super Future, and his sophomore LP Future Hendrix, which he's prepping for a late 2012 to early 2013 release. Looking less far ahead, though, download "Trap House With No Doors," a new, tagged track from the Future-hosted Street Runnaz 66 mixtape that features Young Scooter and a nod to shrooming.