Run the Jewels made its late-night TV debut on the Halloween episode of “The Late Show with David Letterman.” With some help from singer-songwriter Boots, Killer Mike and El-P shook up the stage with a frighteningly awesome performance of “Early” off their sophomore album Run the Jewels 2, which has been receiving rave reviews.

The hip-hop duo’s tour kicked off in Philly last night. To celebrate, RTJ’s DJ Trackstar put out a mixtape, which can be downloaded here.