Serenatas is the Spanish word for "serenades". It describes the classic romantic gesture of performing a song for a loved one, traditionally sung at night beneath their window.
In this song, Jerry Rivera sings that the person who gives serenatas is now considered old-fashioned. He uses this beautiful, culturally-rich word to evoke a nostalgic and passionate kind of love that he feels is disappearing from the world.
Have you ever felt like your love is the last of its kind in a world that’s forgotten what romance is? That's the heart of this song. Jerry Rivera sings about a love that feels increasingly rare, saying, "Amores como el nuestro quedan ya muy pocos" (Loves like ours, there are very few left). He feels that the old ways of showing love are now seen as silly; "Deshojar una rosa es cosa ya de tontos" (Plucking the petals off a rose is now a thing for fools). In his view, this kind of deep, committed love is "Como los unicornios / Van desapareciendo" (Like unicorns / They are disappearing) in a world where romance has become too easy and superficial.
He gives some very specific examples of how things have changed. He complains that "En los muros casi nadie pinta corazones" (On walls, almost nobody paints hearts anymore) and that modern songs are only about sex, or as he puts it, "De sábanas mojadas hablan las canciones" (The songs talk about wet sheets). He contrasts this with his own love, which he compares to Romeo and Juliet's, calling it eternal. For him, real love is about total commitment: "Estar enamorado / Es darse por completo" (To be in love / Is to give yourself completely). It's a powerful declaration that a love so pure and sacred "No debe morir jamás" (must never die).