STAGE FRIGHT is a Hitchcock film that deserves to be better known. There’s a lot of fuss about the “false flash-back” — BIG DEAL! It’s essential to make the story work and if it’s a flaw it’s an easy one to overlook.
The movie is scripted by Alma Reville (Mrs. H.) and Patricia H. turns up in it and it’s a very familial film, centering on a lovely father-daughter relationship (Jane Wyman and Alastair Sim), with the mother (Edith Sitwell) a bit of a dopey outsider, but lovingly tolerated (as is often the way in Hitchcock — the mothers aren’t always completelyhorrible). Wyman plays a drama student, so we can see her as a bit of a fictionalised Pat (although I wince at the name they’ve given the real Pat’s character: Chubby Bannister.)
Asides from the family aspect, the film is also unusually jam-packed with women. Wyman’s amateur sleuth drives the whole plot forward, and is plucky and sweet, with her whispery voice. Sitwell provides comedy relief, as does a brief cameo by the teeth of Joyce Grenfell. Kay Walsh brings a bitter savagery to her blackmailing cockney role, and there’s even a minute glimpse of the divine Irene (pronounced Irene-y) Handl, as a maid, as usual.

Then there’s Dietrich. Her role is a sort of fusion of her parts in Mitchell Leisen’s THE LADY IS WILLING (shallow diva) and Wilder’s WITNESS FOR THE PROSECUTION (woman scorned). And she sings The Laziest Gal in Town and is magnificent.
Also, Hitchcock is able to design a few shots around her that have a little Sternbergian power, something few other directors managed.

But I do think it was maybe a mistake to assign her the dialogue, “We had a terrible quarrel.” It comes out as ~
“We had a tewibbow quaw-waw.”