Putting a face to the voice

'Ghost' Soprano Marni Nixon, Who Voiced Blockbuster Musicals, Dies At 86 : The Two-Way : NPR

I've probably seen her face before, but I don't recall it.

Well, actually, I definitely had, just that I didn't know it:

After My Fair Lady was released in 1964, Nixon appeared onscreen in only one movie — The Sound of Music — as Sister Sophia, one of the nuns who sing "How Do You Solve a
Problem like Maria?" The film's star — Julie Andrews — didn't need any help in the singing department.