What is all that banging noise in the background of Up with Chris Hayes?

Every week it sounds like there is remodeling going on.

• I was wondering the same thing today. It's not like they were changing the set for the next show, he's on for two hours. And why didn't anyone address it?

• I can only hope it's Ari Melber and Ezra Klein going at it.

• That noise has been there nearly every week since the show started.

• More banging and yelling in the background on 11/24.

• I often think behind the scenes at MSNBC is chaos. There are often just random people walking around the rear of the set while Rachel Maddow (their flagship show, for crying out loud!) is on the air.