By the time MTV and VH1 music videos became daily fare on cable TV, big screen movie musicals were no longer in production as frequently as they were in the 1930s through the 1950s. Society had changed. Hollywood had changed. Most of the original big screen musicals were now animated. For a new generation, music videos were the new musicals that told a story. Michael Jackson's "Beat It" and "Thriller" for example. But there was a huge difference: The purpose of music videos is to promote and market an artist and sell the song. The music video sells the performer's product. The purpose of the musical number in a good movie is to reveal character, express emotion and advance the story when mere spoken word is not enough. Think of Judy Garland singing "Over the Rainbow" in THE WIZARD OF OZ and her memorable introduction of "Have Yourself A Merry Little Christmas" during a poignant family scene in MEET ME IN ST. LOUIS.
The MTV and VH1 generation saw music videos that borrowed from classic movie musicals and their stars to market new music and its artists. The early Whitney Huston music videos borrowed visually from a Fred Astaire number in THE BARKLEYS OF BROADWAY and an Audrey Hepburn number in FUNNY FACE which co-starred Fred Astaire. Astaire's famous ceiling dance in ROYAL WEDDING was copied in a Lionel Richie video. Paula Abdul borrowed from Gene Kelly MGM musicals. Madonna kicked off her music video career imitating Marilyn Monroe's jazzy "Diamonds Are a Girl's Best Friend" number from 1953's GENTLEMEN PREFER BLONDES in her 1980s "Material Girl" video.
Musicals can win Hollywood gold. Yul Brynner won the Best Actor Oscar for THE KING AND I. Rita Moreno won Best Supporting Actress for WEST SIDE STORY. George Chakiris was Best Supporting Actor for the same film. Julie Andrews was Best Actress for MARY POPPINS. Barbra Streisand won Best Actress for FUNNY GIRL, Liza Minnelli won Best Actress for CABARET. Joel Grey won Best Supporting Actor for the same film, Catherine Zeta-Jones won Best Supporting Actress for CHICAGO. Jennifer Hudson was Best Supporting Actress for DREAMGIRLS.
AN AMERICAN IN PARIS (1951) and GIGI (1958) were directed by Vincente Minnelli. Both won Oscars for Best Picture and both were turned into Broadway musicals in recent years.
WEST SIDE STORY (1961), MY FAIR LADY (1964), THE SOUND OF MUSIC (1965) and CHICAGO (2002) won Oscars in the Best Picture category.
Those were all musicals that originated on Broadway.
A few modern musicals did not get quite the attention I feel they deserved. I saw HEDWIG AND THE ANGRY INCH on stage. The movie version rocked. It really opened up the stage vehicle. And if you wanted edgy, this was the tale of a German boy who has a sex change in order to go to America with a black G.I. and become a rock star. He winds up with a band in a Kansas trailer park.
ONCE got the Oscar for Best Song of 2007. A master director like Vincente Minnelli would have loved the innovative way musical numbers were seamlessly introduced in this simple, touching love story. The original musical numbers came about so naturally. A young woman listens to music on her portable device as she walks down the street and sings along. A couple of musicians who will fall in love sit in a music store, play instruments and sing. You almost didn't realize you were seeing a musical number because the song flowed from such a ordinary moment involving music.
From what I saw in the LA LA LAND trailer, the director seems to have been inspired visually by Alfred Hitchcock's VERTIGO. (Heck even Hitch directed a musical.)
Now look at this trailer from LA LA LAND. Pay attention to the visuals.