Actor Allusion: Bob McGrath has a music degree, as well as an established career which predates Sesame Street's run.
Beam Me Up, Scotty!: Cookie Monster has never used the catchphrase "Cookies are a sometimes food!" It was Hoots the Owl who sang "A Cookie Is a Sometimes Food" to Cookie Monster. After the song, Cookie Monster replied "Me get it, cookie is sometimes food. You know what? Right now is sometime!" and devoured the cookie.
Regarding Big Bird's encounter with Sally on Gordon's shoulders in the first episode, Big Bird is always quoted as saying, "Gosh! You're the tallest little girl I've ever seen!" (even Big Bird performer Caroll Spinney says this), however, in the actual episode, Big Bird's reaction is, "Dah! Oh my heavens! She's 8 feet tall!"
Channel Hop: From National Educational Television to PBS, as NET was leaving the airwaves. Not a literal example, as the educational stations airing Sesame Street were the same in virtually every market.
Played straight in the United Kingdom, however (when the show moved from ITV to Channel Four).
Contractual Purity: Kevin Clash was the Muppeteer of Elmo, Baby Sinclair and numerous others. In 2012, he took a sabbatical from Sesame Street after a young man claimed that the two of them had a sexual relationship when he was 16. Clash did not deny the relationship, but claimed it happened after the young man had turned 18. The accuser later withdrew the allegations, but a series of other accusers came forward in its wake. Sesame Workshop expressed their willingness to support Clash, but he decided to resign to spare them the inevitable media scandal that would have resulted. Ryan Dillon has taken over Muppeteering duties for Elmo since.
Two words: Veggie Monster. To paraphrase from the link, Sesame Street did a segment in 2005 where another character sings a song entitled "Cookies Are a Sometimes Food" with Cookie Monster, about eating a balanced diet; at the end Cookie declares that "Now is sometime!" and eats his cookies anyway. The media simplified this and ran with it to the point where to this day, you'll find people complaining that Cookie Monster has been turned into (or even been replaced by) a "Veggie Monster".
Before the debut of Kami, the HIV-positive Muppet, news media were in uproar, under the mistaken impression that this character would feature on the American version of the show. However, the character was only ever intended to be used in the South African version, where childhood HIV and AIDS are huge problems. Likewise, despite some of the more extreme claims, Kami's HIV status does not mean she is gay; by definition, the Muppets do not have a defined sexuality. To make this clearer, Word Of God is that Kami contracted HIV from a blood transfusion as an infant.
The Danza: Bob McGrath, who plays Bob Johnson on the show.
Linda Bove As Herself, and Miles Robinson was originally played by Miles Orman.
Alan Muraoka as Alan.
Christopher Knowings as Chris Robinson.
Ruth Buzzi as Ruthie
The character of Gordon's last name was eventually penned as Robinson, in honor of original writer/producer and Gordon portrayer Matt Robinson.
Sesame Street has had a lot of Danzas. Even Tony himself has appeared as a guest star.
Chris Robinson is supposed to be in High School or College, making him 17-18 in his first season. His actor, Chris Knowings, was actually 27 at the time his debut aired.
Maria celebrated her 21st birthday in 1979. Sonia Manzano, on the other hand, was 29 at the time the episode aired.
In reality, Bill McCutcheon, the actor who portrayed Uncle Wally, was only eight years older than actor Bob McGrath.
Defictionalization: Outside Philadelphia, there's a theme park in Sesame Place. It includes a perfect life-size replica of the set of the show, and the characters come out to greet guests constantly. Yes, you can take photos.
For the show's 40th anniversary, a corner of Manhattan was temporarily renamed 123 Sesame Street.
Directed by Cast Member: By circa 2005, Kevin Clash got more involved behind the scenes, both directing and executive producing (the latter mostly applied to the "Elmo's World" segments, and other Elmo-related projects).
Dueling Shows: The street being brightened and cleaned up for Season 25, in addition to the new Around the Corner setting, and the addition of a ton of new human and Muppet characters (Zoe, in particular) was all because of the competition Sesame Workshop faced from Barney & Friends.
Enforced Method Acting: Subverted in "Goodbye Mister Hooper". The cast did fine in rehearsal, but when the cameras rolled, they barely hung on, and Loretta Long (who played Susan) flubbed a line. Director Jon Stone wanted to try again, but it was too much for the cast, and so executive producer Dulcy Singer decided to keep the scene as is. The footage that the crew kept was the scene that we saw ... and it showed, quite candidly, that even adults cry and genuinely feel deeply saddened when a person they were close to has died, and that children aren't the only ones who become emotional.
Irony as She Is Cast: According to Muppet Wiki, Allison Bartlett O'Reilly is allergic to dogs. However, Gina doesn't treat any real ones.
Missing Episode: The late 1970s episode where Margaret Hamilton reprised◊ her role as The Wicked Witch of the West is currently lost. The one time it aired, numerous parents sent hate mail saying it was too frightening for their children, and at least one Wiccan mother complained that the episode represented negative stereotypes of witches.
The episode "Snuffy's Parents Get a Divorce" never aired as the test audiences didn't seem to get the concept well. Only one known picture◊ exists of it.
Regarding massive criticism, Katy Perry's "Hot and Cold" segment with Elmo has never been aired on television, due to claims that Perry's dress was too risqu้ for a preschool- to kindergarten-aged educational TV show. While the dress did show some cleavage (behind a mesh panel) and seemed to accentuate her chest in a way that makes it look as if the dress doesn't fit her, most viewers who saw the original sketch on YouTube declared that the ban is yet another sign of parents overreacting to sexuality and near-nudity on TV, yet turning a blind eye to violence, gore, and Nightmare Fuel.
Long-Runner Cast Turnover: During the 1990s, a number of major actors passed away or began to appear less. Season 37 saw the start of another ongoing turnover.
Three actors played Gordon (four if you count Garrett Saunders, the actor in the original test episodes): Matt Robinson for Seasons 1-3, Hal Miller for Seasons 4 and 5, and Roscoe Orman from Season 6 to today. Dr. Loretta Long (Susan) has mentioned that kids have asked her about the other Gordons, making her feel like she's been hiding their bodies under the stoop. Likewise, Gordon and Susan's son, Miles, was played by three different kids as well, first by MilesOrman, then Imani Patterson, and finally Olamide Faison.
Mr. Handford, who took over Hooper's Store after David and before Alan, was played by Leonard Jackson in his debut season, then by David Langston Smyrl for the remainder of his tenure on the show; Roscoe Orman even lampshaded this by comparing the switch to that of Darrin on Bewitched.
On the Muppet spectrum, we have Steve Whitmire for Jim Henson as Kermit the Frog and Ernie, Eric Jacobson for Frank Oz as Bert and Grover, David Rudman for Frank Oz as Cookie Monster, Kevin Clash for Richard Hunt (also for Brian Muehl) as Elmo, Marty Robinson for Brian Muehl as Telly and for Jerry Nelson as Snuffy, and now more recently Matt Vogel for Jerry Nelson as Count Von Count.
For a brief time during the first season, Danny Seagren stepped in as Big Bird while Caroll Spinney had fallen ill and was unable to attend tapings.
Shortly after Will Lee, the actor who played beloved shopkeeper Mr. Hooper, died in December 1982, the producers briefly considered among a variety of options hiring a new actor to play Mr. Hooper. Before the casting call went out, some bright fellow decided the only acceptable option was to address death head on and so it came to pass with Hooper also passing away. (It had been suggested that children who had watched Sesame Street long enough would immediately be able to tell the difference between the Lee Mr. Hooper and any replacement and outright reject him, although ostensibly this was not a big matter when three different actors appeared as Gordon in a matter of two years.)
The Pete Best: Sort of, although the skits in which Herbert Birdsfoot appeared in continued to be re-used into the '90s.
Playing Against Type: Many people (especially kids) wouldn't know this, but this is actually what Gordon and Gina were/are for Roscoe Orman and Alison Bartlett-O'Reilly, respectively. Aside from Gordon, Orman has played a variety of different villainous and unscrupulous characters (including the title role of Willie Dynamite) and on the Law & Order franchise no-nonsense judges. Bartlett-O'Reilly had been frequently typecast as a tough girl, a tomboy (which she attributed to her Brooklyn roots), a disturbed woman, or as a regular on The Sopranos a mobster's girlfriend. Similarly, Sonia Manzano (Maria) has also been typecast as mentally ill (namely on the Law & Order shows) or tough girls. Emilio Delgado (Luis) has generally been cast as a genial person in his off-Street roles, but has played a focused, nose-to-the-grindstone editor on Lou Grant.
Kermit was Put on a Bus because Disney bought out the Muppet Show Muppets. He still appears now and again in the occasional cameo or legacy segment.
In the wake of Hurricane Katrina, PBS reaired the week-long story arc from Season 32 (2001) - with a new introduction with Gordon explaining to parents that children can be frightened by such devastation, whether directly effected by it, or from seeing the coverage on TV. Since then, with devastating hurricanes becoming more commonplace, as of 2012, Sesame Workshop cobbled together the street scenes from the hurricane saga (specifically, the aftermath of the hurricane) into an hour-long special entitled Sesame Street Gets Through a Storm (also known as Friends to the Rescue on DVD), which is subsequently aired on PBS in response to any major hurricane, such as Sandy.
Throw It In: A small-scale version of Zoe was originally built for her role as "Mousey the Hatter Helper" in the direct-to-video Abby in Wonderland movie, but the puppeteers liked it so much that, starting in Season 40, they made this Zoe the de facto Zoe. Sesame Workshop, of course, tested this smaller Zoe by having kids visit the set, and they didn't seem to notice.
A good chunk of Muppet dialogue is ad-libbed, or at least used to be. Watch an old "People in Your Neighborhood" sketch to see Jim Henson try to make Bob crack up.
One recurring feature was having the Muppets interact with children in unscripted segments, resulting in such classic (and adorable) bits as this one.
What Could Have Been: Caroll Spinney was very close to being aboard the Challenger as Big Bird. But the expenses of sending him and the puppet suit into space were enough to keep him off the shuttle and its explosive fate.
Jim Henson originally intended Oscar to be purple, but TV cameras in 1969 couldn't handle that color. The first-season orange Oscar was abandoned for the same reason.
The pilot episodes had the Muppets kept separate from the humans and the street, but since the kids paid more attention to the Muppets in test screenings, the Muppets were wisely integrated.
At one time there was an episode that was supposed to air on September 27, 2010, in which Katy Perry performs a version of "Hot and Cold" with Elmo. However, because the song wasn't kid-friendly enough, and because of the outcry of Media Watchdog groups over her Impossibly-Low Neckline and Absolute Cleavage, Sesame Workshop had to pull the episode a few days before it was to air. You can still watch the video here.
Snuffy's parents were meant to get divorced, but test audiences had a negative reaction to the episode. It's never been aired.
Robert Guillaume was testing for the part of Gordon at the same time Roscoe Orman was.
Sometime in the late 1970s/early 1980s, Sonia Manzano expressed concern to executive producer Dulcy Singer that Latin American culture wasn't being represented on the show very well, so Singer, in turn, suggested that Manzano write the material herself (one of the first things she wrote was the memorable "Hola" song for Maria and Luis); since then, Sonia Manzano has been on Sesame's writing staff (and even wrote a number of children's books based on her childhood experiences).
In addition to joining the Muppet staff in the early 1990s, Joey Mazzarino also got involved in writing for Sesame as well (his first bit was the Columbo parody, "Colambo"), and as of Season 40, is the show's current head writer.
Caroll Spinney pitched ideas that were worked onto the show, but ultimately never received any kind of writing credit for them. This includes the unscripted inserts involving children interacting with the Muppets (such as Joey and Kermit, or John-John and Herry), as well as outlining the entire Big Bird in China special.