Visible crew/equipment: When George and Elaine are in the cab, you can see the studio lights reflected in George's and the cab driver's glasses.
Visible crew/equipment: In the final scene with Larry David guiding Noreen off the bridge, a crew member's arm is visible in the bottom right corner of the screen. (00:22:30)
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