The name "Stella" comes from when the trio first performed at a nightclub, the nightclub's owner, who was six months pregnant told them she was going to name her baby "Stella". The trio then named their act "Stella" as a sign of respect.
In the pilot, Michael, Michael and David's neighbors were Jennifer, Stacy and Karen; Karen was played by Rashida Jones. But after then, Karen disappeared and was replaced by Amy, played by Samantha Buck; nothing else was changed. The pilot was filmed on location in a New York apartment, which explains the differences in lighting and the appearance of the hallway scenes in the subsequent episodes.