How many governesses were there in the sound of music?
12 if you count Maria. 11 if you don't count Maria
Many times, music is played as a part of what is known as the film's "sound track." In many instances, this music is known non-diegetic, that is to say, there no visible source for the sound within the film's story. Diegetic sound is sound that comes from the story, like as an actor strums a guitar.
No. Sound is anything from an explosion to a thousand nails on the blackboard, to the most beautiful music you have ever heard. Music is an organized niche of sound, an area where sound is at it's very best. But while music relies almost 100% on sound, music is not the same thing as sound. Sound is a much broader category.