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)
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)
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)
Revealing mistake: After the scene in which Elaine tells Jerry about her confrontation with the "head-nodding" man, and before the scene where George swallows a fly, the scene cuts to a shot of the exterior of Monk's café. The actual, real-life restaurant used for exterior purposes is named "Tom's Restaurant," and the "m's" in "Tom's" can be seen during this five-second shot. (00:23:00)
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