Agallas literally translates to "gills" (like on a fish), but in this context, it's a colloquial term meaning "guts" or "courage." It's a strong and evocative word that isn't heard in every song.
In the lyrics, "No han de querer verle nunca porque agallas lea" implies that the person being described has immense courage and resilience, making them formidable. This word perfectly captures the tough and determined spirit of the individual in the song.
Aldo Trujillo's "Con Tinta Negra" is all about celebrating a strong, resilient woman named Miriam. He starts by saying, "con tinta negra voy a relatar eso" [with black ink I am going to relate that], promising to tell her story. She's someone who has faced "ocho casos muy duros" [eight very hard cases] but remains incredibly strong and positive, even after life has "golpeado la vida" [hit her life].
He describes her as having a good character but being very pleasant, always responsible at work, and someone who enjoys life. She likes to "escuchando la banda y los tropos para vestir" [listening to banda music and dressing well], with elegant tastes. Miriam is also incredibly loyal to her family, especially her mother, for whom she would "daría la vida" [give her life]. The song ends with her saying goodbye, ready to "la vida disfrutar" [enjoy life] and handle some business, with "números en color verde cortes la capa frontal" [numbers in green, cut the front layer] – maybe referring to money or success. It's a real tribute to her strength and spirit!