Something Rotten is a musical about putting on a musical. Some of the songs are therefore part of the “XXXX: The Musical” they are performing (don’t want to spoil the name of the musical-in-a-musical.)
That episode doesn’t do quite what the OP is looking for, but this one does.
The Scrubs episode “My Musical” is heard as song in universe, the conceit of the episode being a patient (the delightful Stephanie D’Abruzzo) who collapsed at the park hears everything in song. So whenever she is in the scene the cast sings.
Be sure to enjoy “Guy Love”, a great Dr Cox Rant, and the classic “Everything Comes Down to Poo.”
How about The Wizard of Oz? I only remember one musical number from when Dorothy is in Kansas (although it’s a beaut, Over the Rainbow), and I think she is alone when she sings that. All the rest of the songs take place in Oz; maybe that’s just how people, and scarecrows, and tin men, and cowardly lions communicate there. I doubt that all the music in the film is meant to be diegetic, but I don’t remember anything in the movie that directly contradicts the notion, either.
And there’s a scene in My Fair Lady that I always thought was odd. When Eliza is singing Just You Wait about Henry Higgins, it certainly seems to be non-diegetic. But as the song ends Eliza notices that Higgins is watching her and she looks sheepish. If she wasn’t actually singing, why does she act as if she’s been caught doing something embarrassing?
Some, but most of the songs are not: “A Musical,” “Right Hand Man”, “God I Hate Shakespeare”, and “Hard to be a Bard” don’t take place on stage.
Kiss Me Kate also has some songs set on stage, but several are not.
It has been a while since I have seen A Chorus Line, but doesn’t all the singing take place on the stage during auditions and rehearsals?
Yes, but they’re not “show songs”; they’re the chorus members singing about their lives. Only “One” is a show song.
The Oz songs may very well be “real” songs, but “Over the Rainbow” ruins it (by being a non-real (though wonderful!) song) in the movie.
Yep.
True Stories is at least halfway there.
It’s a good word. One of my favorite Archer moments is, IIRC, in one of the “Sea Tunt” episodes where Cheryl is reacting to the background music, finally putting her hands over her ears and exclaiming “It’s not diegetic!”.
“Crazy Ex-Girlfriend” is an interesting mix of these two. The protagonist is mentally ill, and several times in the show it’s mentioned that the songs are actually going on in her head, so they’re dramatizing her thoughts; but she’s aware that they’re going on and that it’s weird, unlike, say, Mary Poppins, where it’s just a fantasy of how things work. And every now and then another character comments on how now the songs are going on in their heads as well.
Then there’s the world of musical revues, which are set up as a concert performance. People just come out and sing songs. An example is Beatlemania, which is designed as a concert by the Beatles, with no real story.
In the early 20th century, there were many of these revues: Ziegfeld Follies, Earl Carroll’s Vanities, etc.
Camp
Victor/Victoria
Joyful Noise
I was thinking that “The Band Wagon” which is about a musical revue (in part) would qualify, but “That’s Entertainment!” and “Shine on my Shoes” don’t fit. That being said, everyone should see “The Band Wagon” - it’s great. You can even (if you squint a bit) see how the numbers in the eventual production would have fit into the musical version of “Faust” which was the original conception of the (in-universe) production.
Three musicals by Dennis Potter are an interesting case.
Pennies From Heaventells the story of a sheet music salesman in the 1930’s. He sees the world in terms of the songs he sells. His philosophy is that “songs tell the truth.” so, when people break out into song, (miming to 1930’s records) it is his perception of the world.
The Singing Detective tells the story of an author who is hospitalized an in considerable pain. He’s writing a script for a film noir style movie, featuring a 1940’s private detective who is also a nightclub singer. His current reality, the film script, and memories from childhood all start to blur at the edges. Some of the songs are real, remembering his father singing, or his detective singing at the nightclub. Others exist in his pain-induced hallucinations. These again used the device of actors miming to old records.
Lipstick on Your Collarused a similar device. IMHO, a pretty weak series.
One of my favorites, the musical episode of Once Upon a Time, “The Song in Your Heart.” A magic spell makes the characters sing, and they’re quite aware of it.
“Heirat” takes place in the boarding house, but if I remember correctly, the two performers are singing along to a record.
The Pineapple song breaks the pattern though - Schultz and the landlady sing that purely as an expression of their feelings (as I recall).
After Hours on The Horrifying Truth About Life Inside of Movie Musicals.