I've decided recently that my hypothesis was unfair: Hollywood's Pinboard does not only apply to action movies, and it isn't a recent phenomenon.
I've decided I like Danny Kaye. He's an actor from the age of Hollywood musicals. I've often expressed the fact that I don't much care for musicals (except, of course, for the undislikable Singing in the Rain), but The Court Jester is excellent family-friendly fare; if you've never seen it, I recommend it highly as good, clean fun. It's also a good introduction to the sort of humor Danny Kaye excels at.
Because my wife and I like Danny Kaye, we'll occasionally pick up a movie he's in without knowing anything about it except that he's in it (when movie rentals are free at the local library, there's no real risk in random movie selection). Sometimes we do well (On The Double was a non-musical comedy that had some surprisingly hilarious moments despite its fairly straightforward comedy-of-errors formula), but sometimes we don't.
On The Riviera is a 1951 musical that stars Danny Kaye, and it made me realize just how accurate my beliefs about a Hollywood Pinboard must be. It functioned like a lot of other musicals (White Christmas, which Danny Kaye is also in, comes to mind) in that its protagonist has a career as a musical performer, so throwing unrelated dance numbers together becomes child's play, but this movie went one step farther:
There's a scene in which a party is going on, which the protagonist (Danny Kaye) was at but has left. Now, the protagonist has recently gotten a big break: a television studio wants to broadcast his stage show because his impersonations of a famous aviator (also Danny Kaye) have been making such a big splash. So he runs off to do his broadcast, and some people at the party gather around the TV to see his show. But instead of his impersonations, he does this number, which I imagine had been on a yellowing sticky note on the Hollywood Pinboard for years before someone finally said, "Okay, fine. Fine! We'll throw it in the next movie we do." This scene simultaneously demonstrates 1) why I don't like musicals and 2) why I do like Danny Kaye. It's complicated, I know. If you can sit through this video, you'll get to see Danny Kaye slaughter the pronunciation of various animals and plants, and it makes me giggle, but the song is grating and the scene had absolutely nothing to do with the rest of the movie: it was never alluded to beforehand; it was never mentioned afterward. And I imagine it was really expensive, with all the harnesses etc. How was it deemed worth the time and money?
No wonder musicals don't exist anymore....
Anyway. I give you the final death throes of musical cinema: