Juerga refers to a lively party, a spree, or a night out, often implying a boisterous and fun time.
In the song, the line "Las noches de juerga se vuelven amargas" (The party nights turn bitter) uses juerga to highlight the contrast between what should be joyful occasions and the singer's current state of sadness. It's a less common, more colloquial word than fiesta, making it interesting and memorable in this context.
Amaral's "Sin Ti No Soy Nada" [Without You I Am Nothing] is a powerful song about feeling completely lost and empty without someone you love. The singer describes herself as "una gota de lluvia mojando mi cara" [a raindrop wetting my face], small and insignificant. Her world is tiny, and her heart is "pedacitos de hielo" [little pieces of ice].
She admits she used to think love wasn't real, just an illusion that always ends. But now, without this person, she's nothing. Even nights out become bitter, and she laughs without genuine joy, with "una sonrisa pintada en la cara" [a painted smile on her face]. She feels like an actor who forgot her lines, and her soul, body, and voice are useless. The song is a desperate plea, wondering what she wouldn't give "por tener tu mirada" [to have your gaze] and to be together "mientras todo cambia" [while everything changes]. It's a raw expression of how one person can become the entire world.