Exclusive! Behind the scenes of ''Sesame Street'''s celebrity week — the most coveted gig in Hollywood

Uh-oh. Sarah Michelle Gellar is in tears, and she’s having a hard time composing herself in front of her red-faced costar. ”You are just magic,” she gushes after one take. ”I am just so in awe of everything you do.” Her scene partner takes the awkward moment in stride — he’s used to it, after all. He’s Elmo, and he’s been sending stars into giggly, giddy freak-outs all week long.

Once a year, the storied children’s-television institution known as Sesame Street packs up its puppets for the West Coast to film scenes with big names who might not be able to make it to the Queens set. During one week in April, the likes of Charlize Theron, Halle Berry, Jon Hamm, Melissa McCarthy, and Don Cheadle showed up at a Hollywood soundstage, where they explained words like innovation, vote, and remember to Elmo and Zoe. (Most of the segments will run throughout the 43rd season, which premieres Sept. 24 on PBS.) ”We call it a celebrity car wash,” says head writer and puppeteer Joey Mazzarino. ”Every 45 minutes there’s a new star walking through the door.”

Unlike so many projects in this town, Sesame Street has little trouble getting celebrities to sign on. More than 400 A-listers — from Oprah to Johnny Cash — have spent time on the Street dating back to season 1, when James Earl Jones flawlessly enunciated the alphabet. ”We have a long list of people dying to be on,” says exec producer Carol-Lynn Parente. ”It comes down to who is available and what type of skit we need to film.” (Two famous faces Sesame has yet to land: Bruce Springsteen and Barbra Streisand, who’ve turned down multiple offers to appear on the show.) Whether a tot recognizes Jon Hamm is irrelevant; Parente says research shows that children who watch with a parent learn better — and Mom and Dad are more likely to watch if they see a celebrity.

While stars don’t pick their puppet, they do get script approval. ”I try to write the script for the person, depending on if it’s a comedy star or sports figure,” says Mazzarino. ”But I love when people like Melissa McCarthy or Steve Carell come in and improv.” Scoring a Street gig is like landing a front-row seat at the Oscars. ”I begged them to let me do it,” says Gellar, whose 2-year-old daughter, Charlotte, is treated to an impromptu rendition of ”Charlotte’s World” courtesy of Elmo. ”I said I’d fire my representation if I didn’t get to do this.” After shooting a bit about the word reinforce, Joseph Gordon-Levitt is clearly reluctant to leave. Taking off his mic, he says, ”Do you want me to do another take? I will. I’ll stay all day if you want!”

Not that there aren’t mishaps with the Muppets. Dax Shepard, who was a last-minute add after Nathan Fillion threw out his back, slips in a ”heck” in one take (”I’ve said some stupid things in my life, but not like this,” he jokes), while Gordon-Levitt ad-libs, ”Did you ever notice that Grover has the same voice as Yoda?” Kevin Clash, the big, bald 52-year-old who voices Elmo, quickly fires back, ”You can’t say that!” And then there was the problem with the word proud, which was first offered to Halle Berry but then given to Timothy Olyphant when Berry’s team didn’t approve the script in time. ”She came in having prepared for [proud],” says Mazzarino, who quickly gave her a skit for the word nibble. ”Her people were yelling at our people. But it didn’t matter. She was really funny. I told her she should do more comedy.” Still, it’s unlikely that any segment this season will spark more controversy than Katy Perry’s appearance in 2010, which was pulled after parents complained that her costume was inappropriate. ”That was such a non-thing. I was there with my kid and didn’t think anything of it,” scoffs Mazzarino. ”I felt really bad. She was so lovely and donated her time.”

Even the puppeteers have their messy moments. It takes many cups of hot water to keep Elmo’s voice at that high octave for the long 8-to-10-hour days. Every so often, Elmo opens his mouth and the puppeteer’s deep voice emerges. ”What’s happening to me?” Elmo says in Clash’s voice during Gellar’s segment. Quips the actress, ”Elmo goes through puberty, on a very special episode of Sesame Street.”

By the end of the week, 20 segments have been shot — and several more celebrity cameos will be filmed on the Sesame Street set in New York. ”Doing Elmo that week is like babysitting a 3½-year-old,” says Clash. ”You’re up at eight, shooting at nine, and going all day until seven,” he laughs. ”Once you take off [the costume], you realize you’re human. And old.”

The Guest Stars

1. When Charlize Theron wasn’t showing off her son, Jackson (who was adopted just weeks earlier), to Elmo, she was teaching Abby Cadabby about the word jealous. As in, even Oscar winners get jealous of fairy wings.

2. The Dark Knight Rises star (who — awwww! — brought along his mom) got quite a primal rush while teaching the word reinforce to Murray. ”There’s a definite opportunity for a proper Three Stooges moment here,” he told the director about the skit where Murray bangs and bangs and bangs a well-reinforced box containing Joseph Gordon-Levitt’s prized watch.

3. ”I never thought they’d ask me,” says actress Paula Patton (seen here primping Abby), who couldn’t stop beaming about being invited to act out the word innovation alongside a futuristic Elmo and a robot. ”I don’t really look at [Kevin Clash]. I just focus on the furry little red guy.”

4. ”It’s the easiest yes to say in the business,” the Modern Family actor tells EW after shooting a segment with Abby about the word remember. During filming, Eric Stonestreet worried that his face was too sweaty. ”Am I too salty?” he asked Abby’s puppeteer, Leslie Carrara-Rudolph.

5. Kristen Bell got the word splatter, which meant take after take of pretending to have ketchup and mustard thrown on her. ”I told Kristen maybe we should make a video with [Elmo] for our future kids,” says Bell’s fiancé, Dax Shepard, who did his skit the following day. ”Hopefully they’ll let me come back. They’ve been around for 43 seasons. I think they’ll still be around then.”

6. Surprised to see the usually stony Justified star smiling? Timothy Olyphant wasn’t the only one who couldn’t keep a straight face when acting opposite the Sesame Street cast. ”I love watching celebrities come to Sesame Street,” says Kevin Clash. ”Their eyes turn into 5-year-olds. You can tell it’s special to them.”

7. Halle Berry showed her strong improvisational skills when she got the word nibble at the last minute, pretending to be scared of a t-t-t-t-tiger that takes a delicate bite of pizza.

Sesame Street
  • TV Show