Note that Ole Rasmussen and his Nebraska Cornhuskers were playing. Ole wasn't a musician himself, but I understand he ran a great Western Swing band. Naturally, the Nebraska Cornhuskers were a California band. I found the photo of the band shown below in a post at The Steele Guitar Forum. This photo is also from the late 1940s, although it was not taken at the Pavalon. (I've been listening to a lot of 78s lately, and I'm developing a bit of a soft spot in my heart for Western Swing. You could do worse than Spade Cooley's "Oklahoma Stomp.")
Sorry these posts are a little thin, folks. I've been writing a long article for the forthcoming Orange Countiana (Vol. 7), and it's eating some of my spare time. I'm enjoying the chance to tell a story in more depth and do more original research. But I'm also a little more anxious than usual about doing this right, because I'll be sharing the pages of Vol. 7 with historians I greatly respect. Anyway, I think you'll find the subject interesting, even if it's obvious that I'm the new kid among practiced pros.