When you host a talk show with interviews, you’re dependent on your guests turning up prepared to entertain the audience. Most guests only appear on these shows when they have something to promote, and some of them will go years between appearances. If they’re a big enough name, the audience will be excited to see them, the host will be psyched and prepared to talk with them, and the hope is that something magical will happen — but it can only work if the guest makes an effort.

That didn’t happen last night when Eddie Murphy sat down with David Letterman. Murphy, who’s promoting “Tower Heist” (in which he seems to be doing an older version of Billy Ray Valentine from “Trading Places”), got a big ovation from the crowd, but when he sat down, he didn’t have much to offer. I’m assuming there was a pre-interview, as there always is for these shows, in which one of Letterman’s producers spoke to Murphy about what he wanted to discuss on the air, which helps the host lead the guest to the topic. Whatever that was, Murphy didn’t come through. Letterman gave him multiple opportunities, but Murphy never swung at the ball, never riffed on anything funny, never did much of anything except laugh at Letterman’s remarks and give frustratingly-short answers.

You know a Letterman interview is in the tank when Dave starts reading off a list of movies the big-name guest has appeared in, hoping that one of them will spark a hilarious anecdote. He tried that with Eddie, but it went nowhere. Nor did he have much to say about his upcoming gig hosting the Oscars, a topic that should be ripe for comedy since Dave gave that a shot once and still regrets it.

Towards the end, when the conversation rolled around to the movie he was there to promote, Murphy had literally nothing to say about it. He didn’t even know which “Tower Heist” clip they were going to show, which led Letterman to exclaim, “Oh, for chrissakes, do I have to do everything? Eddie, you’re not even trying!”

It’s been a very long time since Murphy has done anything successful that didn’t have the word “Shrek” in it, but I’m sure that he’s still surrounded by sycophants who tell him that every syllable he utters is hysterical, that he’s a comedic genius, that he’s an amazing storyteller. If any of those are true, he’s certainly keeping them away from the TV cameras.

Here’s Letterman earning every bit of his salary, trying to pull any entertaining morsel out of his guest last night…