Factual error: In scene where Tommy is selling his hot stuff, he is talking to Bob Gaudio. A modern plastic screw top Coke bottle can be seen peeking out from behind a crate. (00:41:26)
Factual error: Taxi cab that drops off Frankie and Bob at Brill Building (early 60s) says $1.00 for first 1/9 mile and 10 cents for each 1/9 mile thereafter. That was the rate starting 04/1980. The rate for early 60s (which started 07/1952) was 25 cents for the first 1/5 mile and five cents for each 1/5 mile thereafter. The next increase came in 12/1964 when the first 1/5 mile jumped to 35 cents. (00:43:20)
Continuity mistake: In the scene where Tommy is arguing with Bob Crewe after the song "Trance", Tommy puts his arm up on the music stand while he argues. In the next shot Tommy's arms are now at his side. When the camera comes back to Tommy, his arm is on the music stand again. (00:49:50)
Audio problem: In a shot during the scene with "Big Girls Don't Cry," when Frankie Valli sings, "Baby, I was cruel," the soundtrack is going, they're dancing, but Frankie is not singing - or at least, his lips aren't moving. (01:00:20)
Factual error: "Can't take my eyes off you" was released in May 1967. The recording scene of this song shows an Ampeg SVT amplifier in the background. Ampeg SVT was not available before 1969 and the specific model shown on the scene (with white rocker toggle) is a later 1976-1979 model. (01:54:10)
Factual error: The movie's opening scenes take place in 1951. Frankie sings a line from the Rays' "Silhouettes," a song which was released in 1957.
Factual error: In the scene in the church, there is an altar facing the people as well as one facing away from the people. The altar facing the people was not introduced until the 1960s, after the scene took place.
Factual error: The TV cameras on the Ed Sullivan Show are shown to be RCA TK-60 cameras which are black and white. The Four Seasons appearance depicted I believe takes place in 1966, but CBS had converted the studio used for the Sullivan show to color in 1965. Therefore the TK60 B&W cameras would not have been used.
Factual error: In the recording studio, before Bob Gaudio is asked to join the group, one of the guys mentions that Gaudio wrote "Short Shorts" for the Royal Teens and the song is "#2 with a bullet." The song never got higher than #3 on the Billboard chart. That was in February of 1958, and fast-moving songs did not have a special symbol until August of 1958, when stars began to be used. The stars were replaced by bullets in June of 1983.
Factual error: In the party scene at Bob Crewe's house, shortly after the Four Seasons have met him at his office, there is a framed copy of Andy Warhol's Campbell soup can, which was not produced until 1962. This party scene most certainly would have been years prior to 1962, as Crewe began collaborating with Bob Guado in 1960 and "Sherry" was the first major record success by the Four Season's, also to hit the airwaves in 1962.