I'm getting so goooood at sleuthing this guy's videos. He has no idea where this is - only identified as "California" in the 40s. He's right about the decade. But CA is a very big state. I got the first part of the video pretty quickly because a) it looked really familiar and b) the Kelly Music Building gave it away, as that's a historical landmark. Westwood Blvd. in the 1940s. That entire sequence is Westwood, including all the houses.
Once it switches to the night footage it's obvious we're in downtown LA but where??? Then we pass a movie marquee and since the double bill is easy to read, it was easy to research. Not. Top-billed Champagne Waltz opened in early 1937. Easy. Second feature, The Young in Heart opened in late 1938, so, not so easy all of a sudden. Obviously, the double bill had to have been in 1939 when The Young in Heart went wide. But nope, nothing. It played like crazy but never on this double bill. And what theater was it. My eyes finally lit on the side of the marquee, which rather than listing the movies, had something else written on it. Took me a minute but I got it - Merritt Building. Well, still there at Broadway and 8th. Once I knew that was the corner I knew it was the Olympic Theater and that we're driving down 8th towards B'way, which is exactly where the Maxwell House coffee shop was until the 1950s. From there, I simply searched Champagne Waltz and Olympic and for each year from 39 on. And finally found it - March 4, 1942, a full five years after Champagne Waltz first came out. Go know. They love me on this guy's YouTube channel
https://youtu.be/eMFRJqddlqc Westwood stuff is at the start - theater appears around 6:50.