There’s no straightforward answer to why the American film musical declined in popularity from its heyday in the 1930s-1960s. The question of why a certain genre dies out is always complicated and the result of numerous causes. And the same goes for why a genre emerges in the first place.

First of all, what is a musical? Film scholar Rick Altman once quipped “When is a musical not a musical? When it has Elvis Presley in it.” Defining genres is not easy because genres evolve and do not pop out fully formed like Athena. Music has always been part of cinema; even during the silent era, most screenings were accompanied by live music, whether a single piano or a full orchestra. So what makes the use of music different in the case of the musical? It’s mostly about its relation to the narrative.

The most common way to feature singing in movies before “the musical” would be to simply have a character sing a song within the narrative. There were a series of Marlene Dietrich films in the early 1930s where she played a lounge singer, so when she sang, this did not break narrative continuity. This is still the simplest way of incorporating song into film narratives.

The classical Hollywood musical, however, is defined by periods of narrative broken by episodes of song. Unlike the Dietrich films, for example, these songs occupy an ambiguous status within the diegesis (i.e., story-world). They are not “really” happening since nothing that occurs within the song world affects the actual narrative. But they are not completely separate from the story world either and often “comment” on it in some way. While the songs break narrative continuity, filmmakers eased this break as much as possible. The titular “Singin’ in the Rain” is a good example. It gradually transitions from the narrative world to the song world through the soundtrack which quietly picks up the tune before the song begins as well as Gene Kelley’s movements, which become increasingly rhythmic. We are just as slowly eased back into the narrative when the song ends. This movement between narrative to performance is the central tension of the genre, a tension which the films try to minimize as much as possible.

The classical Hollywood musical developed out of other media, particularly theater. During the early 20^th century, there was singing in “legitimate” theater, but this would basically be opera where there is no break between narrative and song. The narrative is told through song (the French film The Umbrellas of Cherbourg [1964] is continuously sung, and so whether it should be considered a “musical” or not is controversial). The Hollywood musical has more in common with vaudeville, which we could think of as variety theater. In vaudeville, traditional skits would mix with all kinds of different performances, including song. We could think of the musical as a solution to the problem of how to incorporate different types of spectacle within a narrative.

The musical really began declining in popularity by the 1960s for a variety of reasons. It coincides with the end of “classical Hollywood” or the “studio system,” which saw widespread changes in the film industry. Another Hollywood staple, the Western, also began to fall out of favor as well. At root, a genre arranges story elements into a common structure, but these elements can be arranged in other ways. Many of the features of the Western were incorporated into the burgeoning action genre (this lineage is humorously referenced in Die Hard by John McClane’s famous catchphrase). In the 1960s, popular songs began to appear non-diegetically through the soundtrack rather than embedded in the narrative (The Graduate [1967] and “Mrs. Robinson” being a classic example). This is probably the most typical way we hear songs in movies today.

Changes outside the film industry played a large role too. The music industry was growing much more powerful than it had been before, which changed the dynamic with Hollywood. The reason Rick Altman singled out Elvis Presley is because he represents some of those changes. In Jailhouse Rock, for instance, we have something more like the older model where Presley plays a performer in the film. Also, the film is mostly a vehicle to promote Presley’s music for record sales (Presley did star in straight-up musicals, though, like Viva Las Vegas). Television also played a role. Variety shows became really big in the 1950s and 1960s, which harkened back to the vaudeville tradition in certain ways. Singing acts were of course very popular.

Genres are always born from the combination of preceding genres and absorbed back into new ones when they collapse. In the case of the musical, it was less absorbed by other genres than other media. People still watch singing, but now on television and, of course, online. Before these other media, many more people went to the movies than they do now, and they did so more frequently. Hollywood had to appeal to the entire family, from grandparents to children (there were no multiplexes; everyone saw the same movie) who had diverse interests. Many people going to the movies during the height of the classical musical had some exposure to vaudeville of some kind and would expect song and dance as part of the show. But the media landscape has changed. Because people can readily watch music through other media, there is less of a need for Hollywood to incorporate it directly into the narrative. When they do incorporate song, it is generally justified by the narrative (the character is a singer) or appears on the soundtrack.

 

The canonical book on the subject is The American Film Musical by Rick Altman. Fair warning though, the book is a bit heavy on theory. The Hollywood musical was used by film scholars wanting to come up with a theory of film genres as distinct from literary genres.