Regarding what you say about music, I have noted that most modern musicals - whether Disney animated features or live action - lack the instant earworms of yesteryear. The Wizard of Oz, Singin' in the Rain, Guys and Dolls, West Side Story, Mary Poppins, The Sound of Music, Oliver!, etc all feature an embarrassment of musical riches that are instantly memorable. With Disney animated films, I remember leaving the cinema with, say, Bear Necessities from The Jungle Book or Under the Sea from The Little Mermaid still running through my head. That simply doesn't happen anymore.