This is an appearance by Colbert when he was a guest on Meyer's Late Night show, and conversation got around to when they were both at Northwestern, briefly overlapping. And they decide to try and remember if they can sing the school fight song.
The actual words, by the way, are --
Go U Northwestern.
Break right through that line.
With your colors flying
We will cheer you all the time.
(U rah rah!)
Go U Northwestern
Fight for victory.
Spread far the fame
Of our fair name
And Go Northwestern,
Win that game!
Let's see how close they come...