Tracy's headboard bookshelf clearly shows three Disney's 'Annette' books. One of the books, "The Mystery at Smugglers Cove", was not published until 1963. The books are visible during the "Good Morning Baltimore" and "Without Love" numbers.
During the initial song "Good morning, Baltimore", Tracy is walking on the street. She stops while singing and on the bottom right is the back of a Cadillac. The 1963-style tail fin and 2 square lights below it are visible.
In a classroom scene, the elevation of Mount Everest is listed on the green board as 29,035 feet. Although this information is correct, the correct elevation of Everest could not be determined before GPS (Global Positioning System) technology. At the time the events in the movie were to have occurred (1962), the accepted elevation of Mount Everest was 29,028 feet.
During the first musical number 'Good Morning Baltimore', Tracy runs across the street from an Esso to look at her reflection in a store window. In this window passed Tracy's reflection a modern plastic water cooler can be seen in the store. The water cooler has a red and blue button with a blue light in the indent for the water spout.
In the movie opening scenes, the newspaper shown is dated May 3, 1962. However, the headlines refer to events that occurred in September of '62 (Liston-Patterson fight and also Barnett defying Supreme Court's ruling to allow Negroes to attend Mississippi University).
In the "Miss Teenage Hairspray" scenes within the TV studio, the opening of the show uses moving lights which weren't introduced until the late 80s, despite the attention to detail using lighting fixtures appropriate to the period in the TV studio
In "Welcome to the 60s", Edna and Mr Pinky are negotiating Tracy's contract. Edna asks Mr Pinky to 'throw in a bustier'. The word 'bustier' did not enter the English language until the 1970s, some ten years after the film is set. Incidentally, the outfit that Edna is later seen in is not a bustier.
There are a number of musical anachronisms: songs, LPs that were not yet available in 1962. The Top 10 chart on the CC Show has "Leader of the Pack" and other songs yet to be released. Motormouth's record store racks show, among others, Junior Walker & the All-Stars' "Road-Runner" LP, Smokey Robinson & the Miracles' "A Pocketfull of Miracles" LP, and a Marvin Gaye & Tammi Terrell LP, all not released for another few years.
Whem Penny and Tracy's Parents are watching the show, the characters are introducing themselves. When Tracy introduces herself, you can hear Edna scream, but it is obviously fake because the scream is way too low and her lips and the scream are out of sync.
During the history class scene right before "Run and Tell
That" the teacher writes on the board about the First Continental Congress in Philadelphia. He writes September 1st, but the correct date is September 5th, 1775, when it first convened.
All during the movie, the blond portions of Tracy's hair change. The blond streaks below her headband don't appear until her first appearance on the Corny Collins show. Especially during "Welcome to the Sixties", the blond streaks above Tracy's headband constantly change, even during the same scene as the camera shots are from different directions or they change locations, such as from room to room in the home and from inside to outside.
During the "Welcome to the 60's" number when everyone is dancing in the street, Tracy and Edna are dancing and swinging their bags. In a closeup of Edna and Tracy, a pink flower falls out of Tracy's hair and lands on the street next to her. In the following wide shot of everyone dancing, the flower isn't visible, nor is it visible in the next closeup of Tracy and Edna.
During the "You Can't Stop the Beat" number, keep an eye on the large board with the bar charts illustrating how many viewers voted for each Miss Hairspray. The bar charts are not consistent between close up and long shots. Close up shots show Amber almost winning, Tracy close on her heels. Long shots during dance numbers show Tracy trailing by quite a bit.
During "Run and Tell That", Seaweed introduces Little Inez, with his arm around her neck which causes her collar to crinkle, but then the camera switches to Tracy and then back to Seaweed and Inez, but the collar is no longer crinkled.
After "I Know Where I've Been", when the crowd is chanting "2, 4, 6, 8, T.V.'s got to integrate," Edna is clutching her white purse under her right forearm, but then the camera pans out and the purse move back to her side.
During the end of 'Run and Tell That', the order in which Tracy, Penny and Link get off the bus changes. Internal shots show Tracy coming off first, then Penny and then Link. When seen from the outside, however, Penny is the first of the three off, followed by Tracy and then Link.
During Tracy's first show on "The Corny Collins Show", Amber is wearing a white layered dress. But a shot during the same scene, where everyone is facing the back of the set, shows Amber wearing the pink and white striped dress that she wears in the beginning of the movie. After that shot, she is back in the white layered dress.
In "Miss Baltimore Crabs" There is a man with a clipboard standing in the background and he disappears from shot to shot. In the same number Penny moves closer and farther away from the group of girls auditioning.
In the scene when Motormouth Maybelle is singing, "I Know Where I've Been", they do 3 quick scenes when Maybelle is singing the lyrics, "There's a dream..." and the crowd behind here sings background. The guy in the stripped shirt is up stage of Tracy, in the next camera pan, he is stage right by 2 people from Tracy. Then, in a quick closeup of Tracy, he is back upstage (behind) Tracy. Then, they pan back to a wide shot of the crowd and he is back stage right of Tracy.
During the opening "Good Morning Baltimore" song segment, a school bus labeled "Patterson School District" passes behind Tracy on the streets of Baltimore. Although she attends Patterson Park High School, it's still the Baltimore School District.
When Penny is taking Tracy's parents to the TV to see Tracy on the Corny Collins Show, Edna says "You think I wanna think [John Glenn]'s really up there?" While some might believe she is referring to the moon landing, which occurred in July 1969 (7 years after the movie takes place), Edna is in fact referring to John Glenn orbiting the Earth, which occurred in February 1962, following the approximate time line for the movie.
In "Timeless To Me," who lit the candle? Edna and Tracy were at Mr. Pinky's shop. When they came back and Tracy went to bed, Edna changed then sang "Big Blond and Beautiful." Edna was then crying on the bed.
In the first "Nicest Kids In Town" number Amber Von Tussle is wearing a stripped pink dress and has her hair done like a bee hive. In the second "Nicest Kids In Town" number you can see a small clip from behind of her wearing the same thing. The first clip was used a second time.
In Geography class after the "Good Morning Baltimore" when the teacher is writing the height of Mt. Everest on the board you can plainly see that it has been written then erased, probably because a retake of the scene.