Cátedra refers to a formal lecture or master class delivered by an expert, often in a university setting. It's a sophisticated and somewhat uncommon word to encounter in a bachata song.
In "Angelito," the narrator says a mysterious angel appeared and "me daba cátedra de amor" (gave me a master class on love). This elevates the angel's advice from simple tips to profound, scholarly wisdom, making the lesson feel vitally important and memorable.
Have you ever been so desperate for someone's love that you'd do anything? In "Angelito," Romeo Santos is in that exact spot. He's had a dream where he tried to please the person he loves, even saying, "Por ti la luna alcancé" [For you, I reached the moon]. But he's lost faith, and in this dream, a mysterious little angel appears to give him some much-needed advice on love.
The angel gives him four rules for surviving this difficult love. First, it's a sin to only think about her. Second, he shouldn't give his life for her, even if he wants to. Third, the angel warns him that his future in love is in danger because of this person. And fourth, the angel tells him that for "un esclavo en el amor, le pisotean el corazón" [a slave in love, they trample on their heart]. The song then points out one of love's weirdest truths: the person who falls for you is probably someone you ignore, while you give your heart to someone else. If that doesn't work out, you lose all faith in love. It's a tough lesson from a dream angel!