"The Wizard of Oz" of course!

When I was little, I liked some of the Abbott & Costello movies.

Of the Shirley Temples, I vote for "Heidi" and "The Little Princess."

I don't know any 4yr olds and I did not really see or appreciate any kid's movies until I was in my late 20's. I have a couple of Ideas anyway.
---That four year old is a good one, already appreciating the classics, she's a keeper!

Fred Astaire's "Easter Parade" is a great movie for kids, it has a lot of big fun numbers.
What about early Laurel and hardy shorts?
Would the "Our Gang" movies be a dumb suggestion? Some of them are pretty funny and have musical numbers, etc.
Nancy Drew Mysteries are not great, but a kid might find them fun and they are not murder mysteries, sort of a kiddie noir, actually.
Good luck.

Today I happen to come upon the site listed below and thought of your four year old here and her appreciation for "The Golden Age of Hollywood".

It is a site of free cut out dolls, many of which are classic film stars, they are done very well, a little girl would approve.
hope this is useful.

100megsfree4.com/gogators4...Stars.html

(They also have some people like Leonardo Di Caprio)