Why does Hector's mother sing the same song that Stanley learned from his parents?

Hector's mother sings the same song that Stanley learned from his parents to emphasize the deep cultural connections and shared experiences between families, regardless of their individual circumstances. The song serves as a bridge between generations, highlighting the importance of tradition and memory in shaping identity. It also illustrates the universal nature of love and longing, resonating with both characters' journeys. Ultimately, it reflects the idea that certain melodies and stories transcend time and place, uniting people through shared heritage.