Vivian Blaine sings "I Walked in with my Eyes Wide Open" to
player piano accompaniment starting about 36 minutes into the film
"Nob Hill" (1945), at http://www.youtube.com/watch?v=as43L9HKU8g 

In this case, they actually focus in on the spool box to show the
words scrolling by, plus a shot of the keyboard in action -- nice
touches, I think.

Lee Rothrock

 [ In the extract at http://www.youtube.com/watch?v=P2AeywPyGpA 
 [ only the song sequence is presented.  Instead of a piano roll,
 [ however, I hear a live piano duet played by skilled studio
 [ pianists; watch the keys move while you listen closely.
 [ Compare the sound with "San Francisco" playing at the beginning
 [ of the film.  -- Robbie