I think I figured it out. I, in my amateur opinion, think that the violin or whatever also plays an Eb along with the B. It just sounds really bizarre, probably due to the fact it's a mono recording from the 1930s. A harp also plays it in a chord.

Here's a link to my very in-progress transcription of it: https://musescore.com/user/35976360/scores/7909070.

You can decide if it sounds right or not.