Piedra angular literally translates to "cornerstone", the essential stone that forms the base of a building. It's a beautiful and uncommon metaphor to find in a reggaeton song.
J. Balvin sings "Tu piedra angular" (Your cornerstone) to describe how essential he was to his ex-partner's life and stability. He's reminding her that he was the fundamental piece holding her world together, making his absence all the more impactful.
Ever had an ex try to crawl back into your life after the ship has already sailed? That is the exact mood in "UN PESO", where Colombian star J. Balvin teams up with Bad Bunny and rock legend Marciano Cantero to shut the door on past drama for good. The core hook revolves around the phrase "Ahora lo que hagas me vale un peso" ["Now whatever you do is worth a single peso to me"], which is a sharp Spanish idiom meaning they simply don't care at all anymore. There is zero room for reconciliation here—they have handed out their forgiveness ("Ya te di tu perdón" ["I already gave you your forgiveness"]), but they have zero desire to bring back old kisses or toxic games.
The track mixes blunt reality checks with vivid images of moving on. Bad Bunny gets cheeky by predicting her regret ("Pensando en mi mientras el café se te enfría" ["Thinking of me while your coffee goes cold"]), noting how she now misses having someone around for breakfast. Then Marciano Cantero drops in to remind her that time ran out, dropping a funny pop-culture nod with "Otros amores también hay / Como la novia de Forrest Gump" ["There are other loves too, like Forrest Gump's girlfriend"]. He used to jump whenever she said frog ("daba un brinco si decías rana"), but that era of being a fool is over. It is a bold, confident track about knowing your worth, letting go of grudges, and letting an ex know that you are totally unbothered.