The hall was filled with her song.

Meaning: This means that the sound of her singing was so loud and clear that it could be heard everywhere in the hall. It's like saying, The sound of her singing was everywhere in the hall.

Choice of Words: The refers to a specific hall. Hall is a large room or passageway in a building. Was filled means to occupy or take up all of the space in something. With indicates that something is accompanied by or contains something else. Her indicates that the song belongs to a specific female. Song refers to a piece of music, typically sung by a person. When you put them together, the sentence "The hall was filled with her song" means that the sound of her singing occupied all of the space in the hall.