Continuity mistake: In the very first shot of Jerry's conversation with George's ex, behind the pile of books you can spot a big lemon slice on the rim of the glass. The slice is then gone from that spot (it's inside the glass now, submerged by the drink), but between shots it is back on and then off again. (00:08:00)
Continuity mistake: Kramer and Jerry are talking about Marlene. Kramer says "Why would George want to deprive you of pleasure? Is it just me?"; he raised both hands chest-high. At the cut, his right hand is lowered. (00:16:00)
Continuity mistake: Kramer leaves with the cantaloupe saying "Well, I am taking this back"; not only he grabbed the fruit during a cut at breakneck speed, but the towel on the station changed also position. (00:17:00)
Continuity mistake: The first time we see Jerry's dad, he's passively taking his wife's whine about The Jacket, remote control on his chest and hands crossed on his belly. Cut, and he is sitting with his arm by his sides. (00:01:00)
Continuity mistake: At the family dinner, Jerry's mom mentions horses for the first time. Reaction shot on the old lady saying "yeah, yeah", and cut to a wider angle; she is now all of a sudden leaning on her right arm. (00:06:50)
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)
Continuity mistake: Jerry called his parents back to tell them about Myra's dead. When his dad at the end of the scene says "You know what this funeral's gonna wind up costing me?" Barney Martin is leaning his head against his hand all of a sudden. (00:12:50)
Continuity mistake: Jerry and his friends are eating, and Elaine opens defending The Pony Remark saying she was just having conversation. She gestures with both hands free, but then at the cut she asks Jerry about the game holding a teaspoon. (00:13:35)
Continuity mistake: During their casual talk about death and wasting your own life, George says he plans to continue wasting it. Cut, and both him and Elaine are in different poses than earlier, with Elaine licking the spoon and George with his fingertips by his mouth. In the majority of the conversation there are no such jumpcuts and continuity is kept. (00:14:45)
Continuity mistake: When Elaine tells George that Jerry must go to the funeral because he could have been the one who killed the old lady, Julia Louis-Dreyfus starts stirring the beverage. The spoon is gone at the cut, and at the following cut it is in her hand, which was free just a second before. Same later when George says that the dead don't care; she is holding it over the cup, but in the next shot it's suddenly inside the cup, hands off. (00:15:15)
Continuity mistake: When Jerry says that Manya's widow is moving to Phoenix, Julia Louis-Dreyfus ' teacup turns 180° between shots. (00:16:15)
The Jacket - S2-E3
Continuity mistake: Jerry asks George in front of the fridge "You don't know Robert Schumann?"; between shots his shirt's collar is suddenly fixed, as earlier it was leaving the tie hanging out at the back. (00:05:50)
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)
The Jacket - S2-E3
Continuity mistake: Jerry powers out of George's grip on his arm to go to the bathroom. Notice Jason Alexander 's right arm; when he is awkwardly smiling at Elaine's dad all of a sudden the coat is entirely under it, while he had the elbow in the middle of it earlier. (00:12:30)
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: 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: When everyone gets up from the lobby seats talking to Alton, George's coat is folded on his arm in two different ways that alternate between shots. (00:17:40)
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: In the shot when Jerry points to Kramer where the ruined jacket is and he walks across the room to go check it out, the box of Ritz crackers is facing The Opposite direction than before, and in the following shot he is holding it in a different way too, by the top of the box instead of the bottom. (00:19:40)
Continuity mistake: George is talking about the phone call; when he says "I don't like to go too long before I ask them out", the waitress with the blue cardigan is passing behind him. At the cut, she's already to the other side of the counter. (00:02:05)
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