This is in reference to the famous painting. If you fell down those stairs, it would look like you were falling up and some spots and down in others. Nobody can tell which way you're falling.
lyrics
So I entered the House Of Stairs
And I walked down
And it felt like I was walking upward more tired
I fell backward and that also brought me toward the ground
I hit a new low and I'm not going any low higher
I hit a new low!
And I'm not going any low higher!
(I hit a new low and I'm not going any low higher!)
(I hit a new low and I'm not going any low higher!)
(I hit a new low and I'm not going any low higher!)
(I hit a new low and I'm not going any low higher!)
(I hit a new low, maybe more, and I'm not going any low higher!)
(Alright, alright, I have the best idea! We're gonna get a harmonica solo! Right here, right now!)
But I don't know how to play the harmonica
"I still don't know how to play it. I don't remember how much it cost me. Um, I bought it, I just don't know how to play it. It's cool to have though. Wait, wait, there's one thing I can do. Wait, hold on. It's like, uh. Here it is, it's pretty cool. Ow! Ow! Something like that. I hit my teeth while doing that. That wasn't even intentional."