Marx Dancing in the Dark

In the movie, Dancer in the Dark, the main character, Selma, frequently has daydreams that result in musical sequences. These sequences are filmed at different camera angles and the overall picture is different. This is because the musical sequences are shot with multiple cameras instead of just the single hand held one that is used for the rest of the movie. However, there is one musical sequence that is different than the rest. The last musical scene or as it is called "The Next to Last Song", is filmed with the same camera angle as the rest of the movie and filmed with the same picture type.
The last musical sequence takes place with Selma about to be hanged. As she is singing, the camera stays with her and the quality of the picture does not change. The fact that this song does not get shot in the same way as the other musical sequences leads me to believe that she was actually singing this time. The other musical sequences involve every other character in the scene. This one scene, nobody else is involved in the singing, and the other characters in the scene are even giving looks as if to say why is she singing?
The other musical scenes involve her escaping her life in some way. The scene before this one, she is singing on her way to the gallows to actually be able to walk. Other times, she is seen singing and dancing while she is at work to delay the monotony. Karl Marx writes that "animals produce onesidedly whilst man produces universally." He also states that "an animal only produces what it immediately nees for its own or its young." In this way, Selma is seen producing like an animal due to the alienation she feels at work.
However, at the end of the movie, with the last musical scene, she is finally producing universally instead of just protecting her young. Her friend is obsessed with trying to save her from death for the good of her son Gene. What is the significance? This way she can still raise him. What is the significance of being able to raise him? Selma, having suffered through the same eye disorder, could help Gene deal with it. What is the significance of having to deal with it? She saved up money to pay for his surgery so he would not suffer later. How does the surgery show she is producing universally? While it seems like it is merely protecting her young, she is clearly not producing for his immediate needs but to satisfy a need that will arise later. What is the significance of her singing by herself then? By singing all by herself she is showing that only through her own alienation can she truly find what she is supposed to do. When she is with the different groups of people she has to act in accordance with them. However, when she's by herself, it is only her making the decisions.