Semblante translates to 'countenance' or 'facial expression'. It's a more formal and evocative word than simply 'cara' (face), suggesting a deeper emotional state reflected on one's face.
In "Canción Del Pasado," Silvio Rodriguez uses semblante to personify the past, stating, "El semblante del pasado es contento, sonríe" (The countenance of the past is content, it smiles). This gives the abstract concept of the past a human quality, making it feel alive and present, which is a key theme of the song.
Silvio Rodriguez's "Canción Del Pasado" is a really interesting look at how the past stays with us. He starts by talking about a woman, and how if she wasn't there, he'd find "un nuevo otra entretenida su pasión amorosa" [a new other to entertain his loving passion]. But even with new passions, the past is still there, like "el semblante del pasado es contento sonríe" [the face of the past is content, it smiles].
He sees the past everywhere, "caminando por casi toda la ciudad" [walking through almost the entire city]. It's in "la gente que se queda, el que se va" [the people who stay, the one who leaves], in his own face, and even in his wife's voice, "a pesar de que lo veo sin querer" [even though I see it unintentionally]. The past isn't just a memory; it's a living thing with "el nombre de millones de sujetos" [the name of millions of subjects], wanting to eat and go to the movies. It even has "un poco de mi nombre y otro poco desde ustedes" [a little bit of my name and another bit of yours]. He calls it "el espectro de un roscón con triple cara" [the specter of a three-faced cake], a constant presence that "la música no apaga" [music doesn't turn off]. It's an instrument that's always playing.