- Hey, It's That Guy!: Al Jardine, Carl Wilson and Dennis Wilson were recruited by Peter Cetera to add the Beach Boys-style vocal harmonies for "Wishing You Were Here" on Chicago VII.
- The Bee Gees sing backup on "Little Miss Lovin'" from Hot Streets, and The Pointer Sisters do the same on "Skinny Boy" from Chicago VII(the song is also found on Robert Lamm's solo album of the same name).
- Saved from Development Hell: Stone of Sisyphus was originally Chicago XXII in 1994. It was eventually released in 2008 as Chicago XXXII, after a label change (the original label was one of the main reasons why it wasn't released in '94) and with one track missing.
- Throw It In: On a lot of the early albums. Many fans got upset when the false start for "Happy Man" got removed from the Rhino remaster of Chicago VII. Also, listen near the end of "Aire" for a more... humorous example.
The original nonmusical play:
- Reality Subtext: The play is Very Loosely Based on a True Story, adapted from cases the author had reported on. The woman Velma was based on attended the original premiere of the play.
The Broadway musical:
- Colbert Bump: Of sorts. The 1996 revival was helped by the real-life O.J. Simpson trial, which highlighted celebrity, murder, and getting away with it.
- Stunt Casting: The revival has become known for casting well known actors and singers in the three lead roles.
The musical film:
- AFIS 100 Years 100 Songs:
- #98, "All That Jazz"
- AFIS Greatest Movie Musicals: #12
- Award Category Fraud: Catherine Zeta-Jones was nominated at the Oscar and BAFTA awards for Best Supporting Actress, even though the role of Velma Kelly in Chicago previously earned Babe Neuworth a Leading Tony.
- Awesome, Dear Boy: Catherine Zeta-Jones was originally approached to play Roxie. Zeta-Jones asked "Who gets to sing 'All That Jazz'?" and when they said "Velma Kelly," she immediately requested to be cast as Velma, even though it was a smaller part, just so she could sing that song.
- Cut Song: A few from the stage show, the most notable being Velma's "I Know a Girl", Roxie and Velma's "My Own Best Friend", and Velma and Mama Morton's "Class". The latter was actually recorded for the film and included on the soundtrack album, but cut from the original print for time.
- Dyeing for Your Art: An interesting example. Even though the script didn't call for it, Catherine Zeta Jones decided to cut her hair short for the role because she was afraid that her ordinarily long hair might obscure her face during the dancing scenes, making the audience think that she had a double doing her dancing for her. With the bob haircut that she wears in the movie, there's no doubt that it's really her.
- Fake Nationality: Katalin Helinski (the Hunyak) is a Hungarian character with a Polish surname played by a Russian actress.
- Hey, It's That Guy! / Creator Cameo: Chita Rivera has a couple lines in the scene before Mama Morton arrives.
- What Could Have Been: