It's been cool to watch Atlanta duo Rich Kidz mature in real time over the past couple years. They're still primarily dedicated to party music, but it's grown increasingly darker and left of center (and occasionally political) compared to the unadulterated glee of their early work. Take their newest song and video, the London On Da Track-produced "Sum 2 Do": whereas 2012's "Nun Else To Do," off their sunshiney Everybody Eat Bread mixtape, held partying over everything, here they've got real things to get off their chest. Download their latest tape, A Westside Story, here.