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)
Audio problem: When Brian is rehearsing with his band, the flautists are heard playing whilst their instruments remain on their laps. (Moments later, the same phrase is repeated, but this time the flautists are playing it).