Whenever a band is the last guest on a late-night talk show, there's always that awkward moment when the host has to walk over and tell them how GREAT they were...even when they clearly don't believe it.

Well, now we know how David Letterman likes to handle the situation...or maybe he just likes beating a joke to death.

Because there's a new montage online of him saying the same thing over and over again to dozens of bands.

He walks over from his desk, looks at the drummer and says, "Are those your drums, or are they rentals?"  Then he usually comments on how great the drum set is.