Julia and Ivy are both big fans of Marilyn Monroe so this is a dream project for them
Michael is a big baseball fan so it is a big deal for him to play Joe DiMaggio
Back for the Finale: Lyle, Leigh, and Jerry all return after extended absences to attend Bombshell in the season one finale.
In the series finale, Michael pops up in the final where-they're-all-headed montage.
Billing Displacement: Debra Messing is top billed, but the show's real stars are Katharine McPhee and Megan Hilty. Even the poster thinks so (witness their positioning).
Additionally, in NBC promos for the show before it aired, "Academy Award Winner Angelica Huston" was often second billed, right after Debra Messing (as she is on the poster above), although a number of other characters are more prominently featured than Ms. Huston's.
Incidentally, although the poster gives Megan Hilty and Katharine McPhee a joint "And Introducing" credit, the series itself doesn't.
Darker and Edgier: Starting with "The Coup", Derek tries to apply this to Marilyn: The Musical. After butting a few heads such darker elements make it in. It even gets a new name: Bombshell. Ultimately this backfires when the Downer Ending turns to be too depressing for a preview audience.
In Season 2, "Hit List" is this compared to "Bombshell."
Dawson Casting: In-universe, when Rebecca Duvall comes on board - it's noted that she's several years older than Marilyn Monroe was when she committed suicide (as is Uma Thurman, who plays Rebecca).
Sam: Yeah, um, isn’t she a little old to be playing Marilyn? Julia: No, she’s perfect. Sam: Yeah but wasn’t Marilyn, like, 36 when she died? Tom: Yes, and Rebecca is 36…ish. Sam: “Ish” being the operative word.
Downer Ending: In "The Producers", Kyle finally gets angry enough at everything Jimmy's done over the past season to kick him out of his apartment, so he packs up all Jimmy's things at his apartment and drops them off at Jimmy's old house... and gets hit by a car on his way home.
Derek: For me to audition, Marilyn herself would have to pop out of that envelope and do me right here.
(Cut to Derek directing a musical number.)
Derek: Five, six, seven, eight...
Hard Work Hardly Works: Averted. Ivy is more experienced and skilled than Karen, and gets the part because of it. Though the Casting Couch might have played into it as well...
And later played straight when Ivy loses the role to Karen in the season finale, despite knowing the part better. When various characters confront Derek with the fact that Ivy is better prepared, he rebukes them by saying that while Karen is green, she just has something that Ivy lacks.
And again in Season 2, when Karen is being directed by Tom and just doesn't seem to get what he wants no matter how hard she works.
At the end of the zig-zag, this is finally averted at the end of the second season: While playing Marilyn does take its toll on Ivy, she has lots of success, and wins the Tony award for Best Actress.
Hollywood Pudgy: Invoked with Karen, but handwaved with Ivy (the actress playing Ivy is of a healthy weight for any reasonable person, yet no one discusses how she's bigger than the rest of the chorus girls).
Karen: Why do I have to be sexy all the time? I wish I was fat. Plus, I'm hungry. I'm gonna start eating more.
In the series finale, it looks like this may be the case with Tom and Patrick Dillon. Then Tom kisses him.
Tom: (smirking) Yeah. That's how all my straight friends kiss me.
"I Want" Song: This series looks like it will be FULL of them. It already has "Let Me Be Your Star", the title of which speaks for itself.
In-Joke: When Eileen, Derek, Tom, and Julia are discussing which direction to take the show in after the workshop, Eileen mentions that 'Joe Machota from CAA' was there, who represents such stars as "Scarlett Johansson, Michelle Williams, Sutton Foster..." At the third name, Tom says "Stop!" Actor Christian Borle and Sutton Foster were married from 2006 to 2010.
Lets Wait Awhile: Sam says this to Tom after the composer tries to make a move on Sam on their first date. Tom is leery, but tentatively agrees to go along with it.
Let's Duet: 1x13 opens with a montage of the main characters packing up and traveling to Boston for their out of town previews. During the montage, we see Tom and Sam at Tom's apartment around his piano, playing around and singing 'Another Opnin', Another Show' which eventually becomes the music for the montage.
Lighter and Softer: The direction Eileen's ex-husband demands Bombshell must take when he temporarily gains control of it. He believes that the Darker and Edgier version Julia wrote the script for with a dramaturg's help would be a huge critical success, but not a money-maker. Eileen, somewhat surprisingly, backs her ex's decision. Julia and Derek both get angry (Derek always wanted a Darker and Edgier version) to the point that Derek quits as director.
Love Dodecahedron: Karen is with Dev who slept with Ivy, who is dating Derek who is also involved with Rebecca.
And now in Season 2, they've added Jimmy, Kyle, and (eventually) Blake and Tom to the mix.
Naïve Newcomer: Both Karen and Ivy have elements of this. Karen is introduced as a small town girl from Iowa trying to make it big in New York but is realistic about how show business operates. In contrast Ivy is a ten year Broadway veteran but still has a lot of naivety about things like the Casting Couch. The other characters lampshade the fact that this makes them a great fit to play the part of Marilyn Monroe.
The adoption subplot in the first season came from Rebeck's own life.
Happens in-universe several times.
Ivy, like Marilyn Monroe, is an up and coming actress who wants to be a star, and she also has problems with prescription drugs and her mother.
Also happens when Michael and Julia are doing a run through of the scene before "Lexington and 52nd" when Michael goes off script. They improv the next few lines, and thus the dialogue that makes it into the play seems to apply exactly to their situation.
Julia is consoling Frank who is afraid he can't trust her after her affair with Michael, even if he wants to by telling him that "the good is bigger than the bad". This gives her the inspiration she needs to complete the lyrics to the final song.
Red Oni, Blue Oni: Ivy and Karen. Ivy is prone to emotional peaks while Karen is far calmer.
Re Tool: Season 2 introduced a second musical and got rid of some of the less popular minor characters from the first season.
Running Gag: For a time, when Eileen's soon-to-be ex-husband Jerry approaches her in a restaurant she throws her drink in his face. Lampshaded when they have a dinner together and he orders her a Manhattan ahead of the conversation so she has something to throw.
Scapegoat: When the workshop presentation fails to attract investors, Tom blames Michael for the failure and Julia and Eileen agree with him. The real reason Tom singled out Michael is because he wants to stop Michael's affair with Julia.
Serenade Your Lover: In episode 14, The Phenomenon, during Tom's flashback, he sings Billy Joel's 'Vienna' to Kyle to distract him from working on new ideas for Hit List.
Show Within a Show: Marilyn: The Musical, later renamed Bombshell, as well as Hitlist in Season 2.
John: Shouldn't we go in? It's supposed to start soon.
Tom: Meh, I heard it's a train wreck.
John: Then why are we seeing it?
Tom and Sam: Because it's a train wreck!
Also Liasons, in the second season. Ivy gets a Tony nomination for her role in it anyway.
Take That: Dig Deep. Tom and Julia add the song after Rebecca Duvall suggests a scene with Marilyn in the Actors' Studio. She's also been complaining that there are too many songs as opposed to scenes. Guess what the song's about? A whole awesome sounding number, that lampoons Lee Strasberg, method acting, Stanislavski and the entire naturalistic school of acting. Funny that Rebecca didn't pick up on that.
In Season 2, the reviews of the Boston preview say that the songs and cast were good, but the show was undermined by Julia's writing ... a slap at Theresa Rebeck, on whom Julia is based but was no longer involved with the show at that point.
Unequal Pairing: Tom and Sam, because Tom is part of the creative staff of Bombshell and Sam is an actor in Bombshell.
Also, Tom and Kyle have a whirlwind romance during the second half of the season. Kyle is both young and a massive fan of Houston and Levitt, and Tom is down after getting lukewarm reviews for his direction and after fighting with Julia.
Vocal Range Exceeded: Rebecca when she first shows up. However she does convince Tom to lower the key, and also hires a vocal coach, so at least she's aware of her limits.
Waiting for a Break: Karen is working as a waitress at the beginning of the series. Fortunately for her, it happens early enough that she can quit by the second episode.
What the Hell, Hero?: Katie has a moment of this with both parents in episode 8 - Her father Jerry's comes via confronting him of the underhanded ways he hid money from Eileen when she needs it most and she has another later in the episode with her mother Eileen after realizing the showcase she experienced was done in without Julia and Tom's prior knowledge and sees their angered/hurt expressions, begging her mother not to stoop to her father's level. Unlike with Jerry, it works almost immediately with Eileen.
Eileen's husband liked to sleep around with blondes until Eileen had enough and filed for divorce.
Julia cheated on her husband Frank with Michael at some point before the series began and they sleep together in episode 6. To complicate things since their last affair, Michael is now married with a kid too
In episode 7, Julia breaks it off with Michael. In episode 9, Frank finds out about the affair and leaves Julia, but they later get back together. In the season one finale, Michael tells Julia that he told his wife, resulting in her(the wife) leaving him
Derek on Ivy, with Rebecca.
Dev and Ivy.
PossiblyEllis on his girlfriend, with Rebecca Duvall's assistant.
Kyle on his boyfriend Blake the Lighting Designer with Tom.
Yo Yo Plot Point: Who will play Marilyn. First Ivy, then Karen, then Ivy again, then Karen, then Rebecca, finally Karen. And then back to Ivy.
Bombshell (The first Show Within a Show, previously titled Marilyn: The Musical) contains examples of: