radiotelefonia wrote:Mary Astor at the piano.
This was in `The Great Lie' (1941). From memory, Astor described the filming of the sequence in her biography as sort-of miming (the book's on loan to someone so I can't double check) - she had to know the piece well enough to be a convincing concert pianist but not actually play it.
However, I've also read other eyewitnesses accounts saying it was virtually all her own work. It would not surprise me at all, as Astor was a highly trained pianist, and also tended to minimise her own role in anything she did.
Going back to the Betty Compson example from `Street Girl' - perhaps it was a similar situation. I was certainly convinced by her performance, and was surprised when I read she'd been dubbed.
Then there's Richard Barthelmess in `Weary River' (1929). Both his voice and piano playing were done `Singin' In The Rain' style by people offscreen, and it caused the first-ever `lip-synching' scandal.