Continuity mistake: Jerry gives Tor the piece of paper to decipher; the paper is curled towards him in the reverse shots, and Tor's hand is placed at a different height - just look at the fold. (00:17:30)
The Revenge - S2-E7
Continuity mistake: George walked back into a meeting at his workplace pretending nothing happened. When his boss enters the room, George repeats in two separate the shots, differently, the gesture to hide his face behind a folder. The folder itself changed position before the boss arrived, since it was in his hand at first, then on the briefcase. (00:08:00)
Continuity mistake: The belligerent paramedic shouts at the driver "I want that Chuckle back, do you hear me?" pointing a finger at the opening, but his arm is on his own leg in the following shot. (00:18:10)
Continuity mistake: George grabs the slip of paper from Elaine's hand. When he has his 'heart attack', in the shot when Jerry says "What does that mean?" the paper goes from his left hand to his right hand. (00:02:45)
Continuity mistake: Elaine hands the ice cream bucket to George. George is holding the plastic spoon against the container, in his left hand. In the close-up he reaches for the spoon off-camera with his right hand. (00:20:45)
Continuity mistake: Elaine and Jerry guessed that George is telling them about a heart attack. Jerry says "I know what this is" pointing a finger - but in the next shot not only the hand is pointing a finger; the hand is holding the yellow note. (00:03:05)
Continuity mistake: Jerry is smothering George with the pillow when Elaine walks in. First shot and a black nurse is walking behind her. Cut for one second to Jerry, back Elaine and the same guy is still walking, exactly where the view cut the first time. (00:06:25)
Revealing mistake: When the two paramedics get off the van to duke it out, look at George lying down in the stretcher. The pillow behind him bears in the last two shots faint purple coloring marks washed out from Jaso Alexander's makeup. (00:18:30)
Continuity mistake: At the beginning of the episode Jerry tells Elaine that he vaguely remembers "doing something"; Julia Louis-Dreyfus puts the remote down and brings her hand up twice in two separate shots. (00:01:30)
Continuity mistake: Elaine walks up to George in bed, and she asks him if anyone's got his apartment yet. For the brief part of dialogue about the zen lifestyle thing, the top sheet is rolled up in a noticeably different way from the rest of the scene. (00:07:00)
The Statue - S2-E6
Continuity mistake: The first time we see Ray, he kisses his fiancée's hand. Elaine in that shot is holding her papers, with the thicker black book closest to her chest. A couple of shots later when he bows to "Jerry, lord of the manor" the books in Elaine's arms have switched position. (00:05:50)
The Statue - S2-E6
Continuity mistake: George had enough of Ray's pawn shop story and jumps up calling him a thief. Watch the couple at the table; the woman, wearing a purple sweater, has her hand on the man's arm in the reaction shot, when nothing of the sort was happening in the wider angle. (00:15:30)
The Statue - S2-E6
Continuity mistake: During the scene at Monk's, Jerry bumps George on purpose making him spill some coffee. George is holding his cup in the right hand and the menu with the left. In the reverse shot you can see Jason Alexander put the cup down, held in his left hand. (00:14:20)
The Jacket - S2-E3
Continuity mistake: When Elaine's dad says "Pipe down, chorus boy" to George, suddenly a hotel staffer in red appears in the recess by the lamp. In another blatant continuity mistake, in the shot that follows George is suddenly without glasses. (00:17:50)
The Jacket - S2-E3
Continuity mistake: Elaine's intimidating father gets up and tells Jerry and George in his gravely voice "I'm going to the bathroom." The newspaper on the table changes spot before and after said shot. (00:15:30)
The Jacket - S2-E3
Continuity mistake: At the end of their strategic break in the men's room, George tosses his paper towel in the bin to the right; however the previous shot ended with Jason Alexander turning around having the towel in his left hand and glancing towards the basket on the left. (00:13:55)
The Jacket - S2-E3
Continuity mistake: In the reaction shot with Alton Benes scoffing at George and Jerry's sissy choice of drinks, a woman with a coat in hand is walking behind him, towards the door. In the next shot, no trace of the woman, just someone in a bicolor puffer. (00:10:25)
Continuity mistake: Jerry and Kramer are arguing about the bet when Kramer is having a glass of milk. The phone rings cutting them off, and Kramer's glass suddenly from his mouth goes to his hip. (00:10:25)
Character mistake: George says that he's paying the chiropractor only half of his $75 bill. However at the end episode Jerry tells George that he gave the chiropractor $35. (00:12:50 - 00:19:20)
Answer: Composer Jonathan Wolff used a synthesizer, although in seasons 7-9, a real bass is used in addition. Wolff also recorded himself making hundreds of mouth noises, pops, and slaps to add to the synthesized bass licks so that each episode has a different theme. The only real "back-story" is Jerry Seinfeld was having trouble coming up with a theme song and talked to a friend who happened to know Wolff. They wanted to avoid that cheesy late 80's sit-com theme song and Wolff came up with what we enjoy now. Jonathan Wolff has also talked about this further in interviews, recently Reed Dunela interviewed him, so for a fuller account of his story; check out "The Wolff of 116th street".
Bishop73