Other mistake: When Finn and Rachel sing Smile in the Choir Room in Mattress (Season 1, Episode 12), Finn doesn't appear to look at any other page but the first one in the music given to him by Rachel. It is unlikely that the entire score for the song was on the first page.
Glee (2009)
1 mistake in Mattress
More quotes from Glee
Trivia: The show is based on creator Ian Brennan's experience in show choir at Prospect High School in Illinois.
Question: Who is the narrator for the previous episode montages?
Answer: According to IMDb.com, Ian Brennan, one of the "Glee" writers and producers, is listed as the uncredited narrator voice.
Michael Albert