Watch Louis CK’s full performance from July 28, 2011.

From Culture Bully:

Louis CK’s performance on last night’s edition of the Late Show with David Letterman was an important one for a number of reasons. The first, and maybe the most notable, is that it marks the former Late Night writer’s return to the show after an unofficial 15 year ban, something Louis spoke to during a recent interview with GQ (via HuffPo), “I loved doing that show. Dave’s my favorite. Dave’s who I watch — I wrote for him. And I did the show five times or so, and I’ve been told that I’m not okay there anymore.”