Tonight is Paul McCartney's first ever performance on Letterman. Believe it or not, he hasn't performed in the Ed Sullivan Theater since 1965 when the Beatles made their final appearance on the stage (here's video from their first appearance). A tipster informs us that currently the outdoor awning is being set up for the performance, meaning he'll also be channeling the famous Beatles rooftop concert in the late '60s (video). He's not the first to take the show outside of the theater, Phish and TV on the Radio have done the same in the past. The performance will be around 5 p.m. today, will the crowd reach Beatle-mania proportions? After this, McCartney will launch what he's called his "final tour" at Citi Field on the 17th. If you happen to be in the area, send us your pictures or tag them with "Gothamist" on flickr!