Cher Pays Tribute to David Letterman: "I Called Him an Asshole on the Air"

Courtesy of CBS

Tom Waits, Dave Grohl and Judd Apatow also offer up their own favorite memories of the 'Late Show' host, whose final show airs May 20.

A version of this story first appeared in the May 22 issue of The Hollywood Reporter magazine. To receive the magazine, click here to subscribe.

So, just how much will David Letterman be missed when he signs off for good on May 20?

Judging by the emotional reactions from some of Hollywood's biggest stars, it's hard to put into words — though "devastated" seems appropriate for "obsessed" fan Judd Apatow.

Here, Apatow and three others reveal their favorite Letterman memories and what they'll miss most about the late-night legend.

Stay tuned to for more memories from other showbiz luminaries as we count down to the final episode of Letterman's Late Show.

Cher (actor, musician)

"I love to make Dave have fun. He's very vulnerable. The first time I met him, I called him an asshole on the air. Trump that anecdote!"

Tom Waits (actor, musician)

"Dave is from Indiana. A lot of my in-laws are from Indiana, so I know what to look out for. Dave is naturally curious, but indifferent, like a dry cleaner taking down your information. He's kind and welcoming, but suspicious and wary. Dave is conflicted; I relate to that. I noticed over the years how many times he'd rephrase my remarks for himself and the audience and find more humor than I ever could. He wants you to sound funnier, and be better than you are and take the credit for it! I also like to do that.

"In the '80s when I first went on Dave's show, I remember him looking at me on the sofa as he sized me up, and it was as if he was saying to me, 'Tom, right now we are working as a comedy team, but let me be clear: I am the major stockholder here soooo … if you are not funny, I will use the ejector button and you will find yourself in another time zone.'

Many people remark on the frigid temperatures in his studio. It is in the low 40s. I was mad at first until it dawned on me that meat looks more appetizing in colder temperatures. Well, let's face it, what is on a TV talk show? People, faces: meat! After that, I enjoyed the climate.

I will miss the down-home choreography of Dave's bendable comedic mind."

Judd Apatow (writer, director, producer)

"In 1986 when I was in college, I was so obsessed with the Late Show that I sent a letter to every member of Letterman's staff asking them how I could get an internship. Someone called and I got a job interview. When I got there, they told me it had been filled. I was so upset I had to take a year off from watching the show.

"The comedy on the show was groundbreaking. At some point Dave decided he was not going to go do many taped pieces featuring himself, but when he did, nobody was better. Him working the drive-through speaker at a fast food restaurant is as funny as it gets. For decades he was constantly innovating the format. Once he did an episode like it was a morning talk show for no particular reason. Another day he did the show while in a jumbo jet. Those shows inspired a generation of writers to push the bounds of their creativity.

"I was only on the show once, when I was promoting Knocked Up. Dave was very warm and it threw me. I hadn't expected him to be so gracious and enthusiastic about me being there. He treated me like a member of the family, and I will never forget it.

"I don't know yet what I miss most about him, but I am already devastated."

Dave Grohl (singer, guitarist, The Foo Fighters)

"The first time we met was in 1995 or 1996 when The Foo Fighters played on the Letterman show. It was our first network television performance and it made perfect sense because I was raised on the Letterman show. I had this tiny black-and-white TV with a crappy antenna in my bedroom in Springfield, Virginia, and I watched his show religiously.

"Dave represented a whole generation of kids like me that sort of looked at life sideways and kind of smiled through the whole thing. I mean, he's just a cool dude so, yeah, our first performance on network television was the Letterman show and I was terrified because it just didn't get much more full-circle than that.

"Standing there onstage and seeing him and then having him walk over and shake my hand like I'd seen him do thousands of times before with other bands but, oh my God, it's like, 'Santa Claus is real!' It's f—ing crazy.

"We played 'This Is a Call.' I think it might have been our first single. Letterman was always great at taking new music, bands and performers that you wouldn't necessarily see on any other television show. Dave was punk rock. The show was really good at choosing non-mainstream musical acts, which I appreciated because I was music-loving, punk rock kid. I always felt like me and my stoner buddies identified with him more than anyone else.

"I don't think anyone in the history of television has seemed as cool and laid back, whether he's got Jim Carrey on the couch or Madonna or the president. I've been on the couch a couple of times, and what I've noticed is that he's genuinely conversational. When you do those shows they do a pre-interview, and when you sit down on the couch the TV host will basically repeat the questions that you've already been asked in pre-interviews and have a 'conversation.' But not with Dave, cause he'll just throw the cards away and start talking about something that he wants to talk about, and that's what it's all about. That's a pro. That's someone that feels completely comfortable and at home sitting in front of a theater full of people asking a stranger really intimate questions.

"It's still crazy to hear him say he's a fan of us. I mean, I'm surprised that we have any fans, but to know that your hero is a real fan — it is more than flattering. It's hard to fathom, it's just like, 'Wow, David Letterman likes punk rock.'

"When Dave had his heart surgery, his first show back he requested that we play the song 'Everlong.' And it was years after that song had been released on record, and we dropped everything to be there. We canceled shows and just made it happen, and the fact that he had asked us to be there for him on such a special occasion really solidified this relationship that we've had since then.

"Worldwide Pants was a huge part of the Sonic Highways series on HBO. And I don't know how many people know that, but when I came up with this idea, I thought, 'Who's gonna help us do this?' Is it a network, is it a production thing? And someone said, 'You should call Worldwide Pants.' So I talked to [Late Show EP] Rob Burnett and Rob said, 'OK, I like the idea. Let me talk to Dave.' And he emailed me back straightaway and said, 'I told Dave. Dave loves the idea and says whatever you got to do to make it happen, make it happen.' And so, if it weren't for Dave I don't know if our last album and that HBO series would have happened.

"We're connected by a few things, but with the perfect amount of distance and a lot of respect. For example, I would never barge into his dressing room and say, 'Hey, man! You want a sandwich?' We gave him a guitar once and he was genuinely touched and we realized not only does he actually like our music but he's a great guy. He's got a heart of f—ing gold and he's just, you know, he will be missed. My mother and I were having this conversation about a week ago, trying to picture life without him. My mother got choked up and started crying. And that made me get choked up?

"I think over the years he's become a part of America's identity. I think that people like me identified with him and his show when I was a teenager, and there's a whole new generation of people that just rely on him for something. And, you know, to imagine that not being a part of your everyday life anymore, it's hard, you know? Weird."