An inordinate amount of musicals are about professional singers and dancers, who are themselves sometimes [[ShowWithinAShow performing in musicals]]. The advantages are obvious -- the creators get to [[WriteWhatYouKnow write what they know]], the characters actually have a good reason to keep breaking into song (this doesn't mean that they don't still break into song ''off'' stage as well), and musical numbers can be thrown in without needing any kind of plot relevance.

Compare MostWritersAreWriters and ThatRemindsMeOfASong.
----
!!Examples:

* All musical biopics, of course -- ''WalkTheLine'' (Johnny Cash), ''Ray'' (Ray Charles), ''La Vie en Rose'' (Edith Piaf), ''GreatBallsOfFire'' (Jerry Lee Lewis), ''Film/YankeeDoodleDandy'' and ''GeorgeM'' (George M. Cohan), and so on, and so forth.
* ''Film/TheBroadwayMelody'' (1929) is probably the first example, or one of the first. Two sisters with a song-and-dance act come to Broadway to make it big.
* ''ShowBoat'', as the title suggests, is about performers on a show boat.
* ''{{Cabaret}}'', as the title suggests, is about performers in a cabaret.
* ''Theatre/KissMeKate'' -- often described as a musical version of ''Theatre/TheTamingOfTheShrew'' -- would be more accurately described as a musical ''about'' a musical version of ''Theatre/TheTamingOfTheShrew''.
* ''TheMusicMan'' is a light example: Harold Hill is selling band instruments, band uniforms and the false promise of starting a band. At the very end the band does wind up performing, once, not very well. The fact that his love interest is a music teacher adds to things a bit.
* ''Theatre/AChorusLine'' features dancers auditioning for a show.
* ''Theatre/{{Chicago}}'' is about a wannabe singer, with the secondary female lead a former singer ("former" because now she's in prison). They both get out of prison and become famous performers.
* ''Easter Parade'' is about a vaudeville dance act.
* ''Film/SinginInTheRain'' is about the making of a musical motion picture.
** Many other Creator/GeneKelly films, including ''For Me And My Gal'' and ''Summer Stock'' (both of which also starred Creator/JudyGarland). A lot of Garland's own films were like this(''Easter Parade'', ''Strike Up The Band'', ''A Star Is Born'') along with Creator/FredAstaire.
** Creator/GeneKelly also made his film debut (''For Me And My Gal'') after being discovered performing in ''Pal Joey'' on Broadway.
* The musical version of ''{{Hairspray}}'' is about the stars of a dance-oriented TV show.
* ''BillyElliot'' is about a boy who wants to be a dancer; the original was a film, but this trope applies to the musical adaptation.
* ''Pal Joey'' is about a nightclub singer.
* ''TheBandWagon'' is about the staging of a musical.
* Baz Luhrman's ''MoulinRouge'' is about a show being put on in the club-turned-theater.
* ''TheSoundOfMusic'' is about a family singing act.
** Also, the "Lonely Goatherd" puppet show.
* ''Film/{{Fame}}'' is set at a performing arts school.
* ''West Point Story'' is about a musical show being put on at West Point.
* In ''Film/TopHat'', Fred Astaire plays a song-and-dance man. There's also ''Easter Parade'' (with Creator/JudyGarland and Ann Miller) and ''Blue Skies'' (also starring BingCrosby). Also ''The Gay Divorcee'', and ''The Barkleys of Broadway'', which featured Ginger Rogers.
* ''{{Once}}'' is about a busker.
* ''TheCommitments'' is about a working-class Irish band.
* Every ''HighSchoolMusical'' film is about the staging of a high school musical.
** Not the second, though it ''is'' about a talent contest that many of the cast members are planning to sing at.
** Even better, the first two films have [[ScreenToStageAdaptation stage adaptations]].
* ''Bye Bye Birdie'' is about a 50s rock singer performing one last concert before he goes off to the army.
* ''ThePhantomOfTheOpera'', strangely enough.
* ''{{Glee}}'' is about a high school glee club.
* ''TitleOfShow'' features friends writing a musical.
** Not only that, but the musical they are writing is [title of show]. They are writing a musical about writing a musical about writing a musical about writing a musical about...
* ''Curtains'' is about a murder investigation on the set of an off-Broadway musical.
* [[Film/TheProducers Springtime for Hitler: A Gay Romp With Eva and Adolf at Berchtesgaden]]
** This is a complicated example: the original film wasn't a musical, it was a film ''about'' a musical (sorta). Then the film was turned ''into'' a musical. Then ''that'' was turned into a film musical.
* ''42nd Street''
* ''{{Smash}}'' is about the conception and production of a Broadway musical.
* Miss Adelaide and the Hotbox Girls in ''GuysAndDolls''.
* ''On The Town'' has the main character(Gene Kelly)'s love interest as an aspiring dancer, though she is currently doing {{Burlesque}}.
* In ''Film/DarlingLili,'' Julie Andrews plays a World War I music hall singer.
* ''{{Sugar}}'' figured that ''SomeLikeItHot'' was ''already'' about a couple of (male) musicians who join an all-female band to get away from the mob; why not turn it into a musical?
* ''TheDrowsyChaperone'' is a about an agoraphobic musical-lover listening to his collection of musical records. His favorite one--''[[ShowWithinAShow The Drowsy Chaperone]]''--which he listens to with the audience, is about the wedding of two 1920s musical stars.
----