Ecko Unlimited is getting ready to release a new compilation showing off some of the finest underground hip-hop acts out there. And to get things rolling, we heard title track "Underground Airplay" this past week. It's led by Joey Bada$$, who weaves in and out of the beat and sets the pace for Smoke DZA and Big K.R.I.T. The latter steals the show yet again—did you hear K.R.I.T.'s "1 Train" verse—and proves he's only getting better with time.