In the movie "The Sound of Music", the protagonist Maria sang the song "Edelweiss" twice. The emotions expressed in the two songs are different. The first time the song was sung, it showed a carefree emotion, while the second time it was sung more heavily, showing longing for and love for the motherland.

The first time she sang "Edelweiss" was after Maria and the captain's wedding, when she played it for the children on the top of the mountain. This singing showed Maria's yearning for a new life and love for children. Her emotions were positive and uplifting.

The second time "Edelweiss" was sung was after Maria and the captain fled Austria. When the captain saw Austria disappearing from sight, he felt great pain, for he was a patriotic man. Maria expressed her longing for and love for her motherland with "Edelweiss", and her emotions were even deeper. This singing also showed Maria's understanding and support for the captain. She comforted the captain with her singing and let him know that their relationship was still strong even after leaving the motherland.

In short, the emotional expression of the protagonist singing the song "Edelweiss" twice in the movie "The Sound of Music" is different. The first singing showed a carefree emotion, while the second singing was heavier, showing longing for and love for the motherland.