Madrugada refers to the very early hours of the morning, typically from midnight to dawn. It's a more specific and evocative term than just saying "morning."
In this song, the artist sings about "Sigo llamándote sin fe en la madrugada" (I keep calling you without faith in the early morning). This word adds a layer of desperation and loneliness, emphasizing the late, quiet hours when he's still reaching out, highlighting the depth of his regret and longing.
Have you ever messed up so badly in a relationship that you just can't stop thinking about it? C.R.O and LIT killah totally get it in "Mi Culpa" [My Fault]. This song is all about the crushing weight of regret after a breakup. The singer is looking at a photo, realizing it's truly over, and he's just stuck on the fact that "Me duele que todo sea mi culpa" [It hurts me that everything is my fault].
He's still calling her in the early hours, even though he's lost hope, and he's haunted by the memory of her, seeing her "por todas partes" [everywhere]. He admits, "Yo sé que he sido lo peor" [I know I've been the worst] and he's desperate for her to tell him "Qué es lo que querés que haga" [What you want me to do]. It's a really honest look at how hard it is to change, even when you know you've hurt someone you love.