Megan Hilty, who plays Ivy Lynn, has played Lorelai Lee in a production of Gentlemen Prefer Blondes. That role was played by Marilyn Monroe in the film of the same name. In the show, Ivy gets to play Marilyn on Broadway.
The "Riedel" whom Julia calls a "Napoleonic little Nazi" and other characters complain about as well is a real person--Michael Riedel, the influential and feared theater columnist for The New York Post, who is well-known for his acerbic-to-scathing reporting on some shows. His writing has occasionally led to conflicts with the theater world off the page as well; one infamous example was when his negative opinion of the 2004 revival of "Fiddler on the Roof" led to the director of that production, David Leveaux, punching Riedel in front of a crowd at the theater district restaurant Angus McIndoe. The real Riedel signed a legal release before the first episode of "Smash" aired allowing the show to call him a "Napoleonic little Nazi."
Several of the actors on Smash have actually performed in Broadway musicals. Megan Hilty played Glinda in Wicked and originated the role of Doralee in 9 to 5. Christian Borle was in the original casts of Spamalot and Peter and the Starcatcher, and originated the role of Emmett in Legally Blonde. Brian d'Arcy James was in the original casts of Titanic, the revival of The Apple Tree, and played the title role in Shrek. Wesley Taylor was in the original casts of Rock of Ages and The Addams Family. Will Chase has been in Rent, Aida, The Full Monty, and Billy Elliot. Ann Harada (Linda) originated the role of Christmas Eve in the puppet musical "Avenue Q." Anjelica Huston has never been in a Broadway musical, but in 1969 she played Ophelia in a Broadway production of Hamlet, and Leslie Odom Jr. Played Aaron Burr in "Hamilton" which he won the Tony Award for best actor for his performance.
It is a running theme, or at least a running gag, for Eileen Rand, portrayed by Anjelica Huston, to throw a drink in the face of her husband (who Eileen is divorcing), Jerry Rand, portrayed by Michael Cristofer. She has done it three times in the first three episodes. It is enough of a gag to be spoofed on the February 20, 2012 showing of 'Late Night with Jimmy Fallon (2009)' when Huston threw a drink in Jimmy Fallon's face. In Season 2, throwing a drink at the camera became Eileen's signature shot in the opening credits.
During the first season of this TV show, in which he plays a Broadway composer, Christian Borle was simultaneously appearing as an actor in an actual Broadway show, playing the role of Black Stache in "Peter and the Starcatcher." In June 2012, Borle won a Tony award for Best Performance by a Featured Actor.
Becky Ann Baker and Dylan Baker, who play Karen's parents, are also married in their real lives. Both are Broadway veterans; he has been in many Broadway plays, including "Eastern Standard" and "God of Carnage," and she was in the original casts of musicals such as "The Best Little Whorehouse in Texas," "Titanic," and "Assassins."
A cast album of Bombshell, the musical about Marilyn Monroe that they make in the show, was recorded and released in the hopes that the show would remain popular enough to bring the musical to the real Broadway stage.
In season 1 episode 3 Eiliene (Anjelica Houston) talks about Ivy Lynn (Megan Hilty) and says "she did a year in Wicked" when in real life Megan Hilty actually played Glinda in Wicked on Broadway for a year
There have been a few brief references to a previous (real-life) attempt at staging a musical about Marilyn Monroe. This was the massive flop "Marilyn: An American Fable," which ran at the Minskoff Theatre for only 34 previews and 17 performances in 1983. The show had a libretto by Patricia Michaels and music and lyrics by Jeanne Napoli, Doug Frank, Gary Portnoy, Beth Lawrence, and Norman Thalheimer. It was directed and choreographed by Kenny Ortega, who went on to choreograph the movie Dirty Dancing, among other projects. The cast included Alyson Reed as Norma Jean/Marilyn Monroe; Scott Bakula as Joe DiMaggio; Kristi Coombs as Young Norma Jean; and Will Gerard as Arthur Miller.
The St. James Theatre, where Eileen initially wants to stage Bombshell, would later host the hit musical Something Rotten! starring Smash stars Brian D'Arcy James, Christian Borle, and later Will Chase.
Brian D'Arcy James and Christian Borle would later go on to star as enemies Nick Bottom and William Shakespeare in the 2015 comedy "Something Rotten!" Both received Tony nominations for their performances, but ultimately Borle won the show's only Tony award overall.
Much of the background music in fancy settings is actually instrumental covers of Broadway hits: for example, a jazzy rendition of "Butter out of Cream" from "Catch Me if You Can" can be heard in a fancy restaurant.