It’s not just to save time during the Oscar show…:
It’s just that very little new music is created specifically for new movies. Tinseltown used to employ a small army of tunesmiths; now it primarily pays for song rights, not songwriters. Most directors prefer to rely on off-the-shelf songs as an evocative way to establish mood and context. For the movie “Goodfellas,” Martin Scorsese used a parade of songs from the ’50s, ’60s and ’70s to set the scenes of each era.
Well you could never pull off a Goodfellas (or a Casino) without pulling from 100s of songs from the era.
Huge music libraries makes it hard for new songs to break through. Every year the worst song on American Idol is the one original tune written for the finals. Even on Broadway, all the new shows seem to be based on 80’s pop songs.
I liked this bit:
The original songs from the Golden Age were often little more than diversions. A standard shtick was to have one of the female characters be a nightclub canary. The romantic lead comes to talk with her backstage, but first he has to sit and listen to her sing something.
Like Marylin Monroe in Some Like it Hot? I for one wasn’t convinced she could play that ukelele: