Does anyone know this film?

I saw a bit of it once and mentioned it to my girlfriend tonight but don’t know and can’t find the name of it.
A rich girl comes to the city hoping to be an actress and stays in some weird hotel with a creepy owner who has some mysterious chinese friends who I believe were running some kind of white meat trade and were trying to get the aforementioned would-be star.
She meets a friend in the hotel who is trying to get a job where she can marry her boss as that’s what ‘modern’ women do.
At a ball in the hotel someone creates a dance called the tapioca.

I think it’s quite old and people often break into song and dance.

And the lift won’t work unless you tap-dance in it.

Anyone who knows the name would be helping me sleep tonight.

I saw this the other day too. But damned if I can remember the name of it. It was a Chinese white slave trade rather than a white meat trade, and there was an awful old woman who kept trying to kill the girl.

Damn, you’ve got me wondering now. I keep thinking “Charade” even though I know it’s not Charade. My boyfriend was watching it with me and he knew the film vaguely, so it’s not that obscure.

This would be Thoroughly Modern Millie starring such luminaries as Julie Andrews, Mary Tyler Moore and Carol Channing. Julie Andrews was trying to be the modern 1920s girl out to marry her boss while Moore was the girl-too-pure-to-be-believed whom the boss actually fell for. It’s kind of funny.