I don't want this to remotely come off as a "trashing" of Marni, but in addition to a beautiful voice, it takes a combination of a special "look" and a uniqueness in presence (often referred to as "it") to become a star. Maybe Marni never had "it." What she also had was a fairly flawless voice ... but it lacked an original quality, which made her ideal for dubbing others. She could be more of a chameleon and assume other personalities (without going overboard) and assist others with their performances.
She's still a legend in my eyes, and it's her voice that I grew up with on those songs from King and I, WSS, and My Fair Lady.
The other thing about Marni's voice is that it was ideally suited for film. It wasn't a big voice. Even perhaps on the thin side, the light side, but when a microphone was pushed right up next to it the way it is for movies, her voice worked perfectly. I think that's why some of the other great stage sopranos never made it in film. Aside from the "it" factor, and the need for a certain look on film, their voices (in my opinion) were too big.
"Jaws is the Citizen Kane of movies."
blocked: logan2, Diamonds3, Hamilton22